Log Length Research Articles

Seasonal Micro-Habitat Relationships of Ruffed Grouse in Southeastern Idaho

We summarized characteristics of micro-habitats selected by ruffed grouse (Bonasa umbellus) in southeastern Idaho for all seasons. Ruffed grouse preferred stands dominated by quaking aspen (Populus tremuloides). Drumming sites selected by males were typified by high vegetation density. Brood hens selected relatively open areas with high cover of herbaceous vegetation. Drumming sites differed (P 2,130 m): quaking aspen, aspen/conifer mixed, dense conifer, and open conifer. A description of each of the vegetation types is in Stauffer and Peterson (1985). Size of stands in each cover type ranged from 23 cm dbh/ha 35 (17) 86 (31) 12 (8) 73 (38) Maple/ha 300 (82) 0 (-) 94 (76) 9 (9) a Sample size. b Standard error. >200 ha. Cover types generally were well interspersed throughout the study area. We spent 1,593 hours (spring, 322 hours; summer, 543 hours; autumn, 296 hours; winter, 432 hours) searching for grouse from May 1979 through May 1981. At these times, an area comprising one or a few vegetation types was selected and thoroughly searched. Searching effort was distributed among each vegetation type in approximate proportion to the type's occurrence on the study area. Locations of grouse flushes were used as the center of a 0.01-ha circular plot for which we recorded (Noon 1981): percent of area within 40 m of the plot center that was comprised of coniferous or deciduous cover or open; percent tree canopy and ground canopy cover; canopy height and average height of herbaceous vegetation; number of woody stems 69 cm); slope; aspect; and vegetation type. Counts of woody stems and trees were converted to number per ha. Additional data recorded at drumming sites included drumming log diameter and length and an ocular estimate of the percent of five strata (0-0.5 m, 0.51-1.5 m, 1.51-3.0 m, 3.01-6.0 m, >6.0 m) with vegetation. Means for data recorded in the 0.01-ha plots at grouse locations were calculated for various combinations of vegetation type and season to describe the characteristics of sites selected. We used Hotelling's T2 and multivariate analysis of variance (MANOVA, Morrison 1976) to test hypotheses of no difference in habitat use by groups of grouse as described in the objectives. We established 150 random plots to sample habitat characteristics assumed available to grouse in aspen and aspen/conifer stands, which were preferred vegetation types (Stauffer and Peterson 1985). Random plot data were subjected to a principal components analysis (Morrison 1976) to reduce the set of correlated variables to independent components that represented habitat gradients occurring within aspen and aspen/conifer stands. We then assigned observations of ruffed grouse in aspen and aspen/conifer vegetation scores on each of the habitat gradients to compare characteristics of microhabitats where we observed ruffed grouse to what was available. Appropriate transformations (log, square-root, or arc-sine) were applied to non-normal variables. RESULTS AND DISCUSSION Ruffed grouse exhibited a preference for sites dominated by aspen (Stauffer and Peterson 1985), thus only data from grouse observations in aspen and aspen/conifer stands (N = 207) are presented here.

Enzyme Levels in Natural Mosquitofish Populations

Adenosine deaminase (ADA), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) activity levels were measured in mosquitofish populations from contrasting natural environments. Significant differences in enzyme level, in the level of soluble protein, and in length and weight were observed among populations from different habitats. MDH and LDH activities were highest in running-water populations, whereas ADA was elevated in coastal environments. Still-water females were longer and weighed less than running-water females. The regression relationships of length vs. weight and protein vs. weight also varied significantly among populations. The proportion of enzyme activity variation which could be accounted for by habitat, location, or log length was not the same for the three enzymes, suggesting that biological and physical factors influence the activities of various enzymes in different ways.

Herbivore Damage to Three Tropical Ferns

Herbivore Damage to Three Tropical Ferns

Species diversity and reproductive mechanisms in Jamaican trees

The flowering and fruiting of the 56 species of tree growing in the forests at c. 1550 m in the western Blue Mountains in Jamaica was studied to see how differences in reproductive biology may relate to maintenance of species diversity. Forty-six of the 56 species have small flowers (log length (mm) × log breadth (mm) 1). Thirty-six are hermaphrodite, 12 dioecious and eight dioecious, monoecious or polygamous. Compatibility tests showed that five (possible seven) of the hermaphrodite species are self-compatible, one hermaphrodite species is probably self-incompatible. Anthesis and individual flower duration are variable within and between species. There is some interspecific temporal separation of flowering over the year, but a peak of species in flower in the drier to early wet season. Pollination syndromes were also studied. Of the 23 important species, 20 are generalist, two wind-pollinated, one bird-pollinated. For all species, 46 are generalist, six wind-pollinated, one, perhaps two, bird-pollinated, and possibly two moth-pollinated. Generalist type flowers are visited by a wide range of potential pollinators and one pollinator, Apis mellifera, visits many different flowers. Dispersal units usually weigh between 10 and 1000 mg, the others are smaller. Of the 23 important species, 18 are adapted for bird dispersal, four for wind dispersal, and one lacks obvious adaptation. For all 56 species 46 are bird-dispersed, eight wind-dispersed, one is ectochoric and one lacks obvious adaptation. Fruiting phenology is markedly seasonal, occurring from June to January, spanning the later drier period and half of the wet season. With one common type of pollination—entomophily, one common type of dispersal—by birds, and little temporal separation over the year in time of flower and fruit production, there seems to be only a small amount of niche separation in the variables studied; and thus the coexistence of many species is not explained by the present observations.

Application of a Small Forwarder in Plantation Thinning

Abstract Thinning the South's managed pine stands is a major problem facing forest landowners in the immediate future. A small log-length forwarder–the Gafner Iron Mule–was examined as a potential improvement to the most common current method–he bobtail truck system. Forwarders are less sensitive to weather and terrain, require less access area in a stand, provide more man-day productivity, and allow greater payloads and less maintenance on highway haul vehicles than the bobtail truck. Travel speeds of the forwarders studied were influenced only by the distance traveled. Loading and unloading were a constant time per swing cycle. Large piles of wood were less expensive to forward than small piles. Production rates were increased and cost rates decreased by increasing the length of logs forwarded.

The effects of sample preparation and measuring techniques on the shape and shape characterization of mineral particles: The case of wollastonite

Shape characterization of mineral particle populations based on a regression analysis of log width dependency on log length was previously shown by H. G. Siegrist and A. G. Wylie (1980, Environ. Res. 23, 348–361) to provide a quantitative basis for distinguishing asbestos from other mineral particles. The derived equations are of the form log width = F log length − b, where F is called the fibrosity index. The sensitivity of F to sample preparation and measuring techniques is evaluated for the mineral wollastonite. A sample of wollastonite was ground by five different techniques in commercially available mills. There were two grinding times for several of the mills. The samples were sieved and representative particles were measured by SEM and PLM. The major results are (1) the accuracy of the shape characterization can be affected by sieving and instrumentation, the range over which length measurements are made, and the number of particles measured; (2) the different methods of grinding have only minor effects on the fibrosity index F; (3) F is essentially independent of particle size, i.e., SEM versus PLM; (4) variations in F between groups of minerals of similar habit far exceed variations due to sample preparation and measuring techniques. These results are valid only for wollastonite and further work is necessary before they can be extrapolated to all fibrous minerals, especially to particles collected on air or water monitoring filters.

Stem eccentricity in coastal western hemlock

Stem eccentricity in second-growth western hemlock (Tsugaheterophylla (Raf.) Sarg.) from southern coastal British Columbia appears to be the rule rather than the exception. Although the difference was small, the average eccentricity ratios (ratios of minimum diameter inside bark (DIB) to maximum DIB) for two Lower Mainland sites were significantly larger than those of two Vancouver Island sites. The average eccentricity ratio of all 87 trees studied was 0.929, with a standard deviation of 0.0231. The angular rotation of the major axis of the stem cross section varied greatly, and was positively related to the average stem eccentricity ratio within 5-m log lengths for each stem. Average eccentricity of the whole stem was relatively independent of diameter at breast height (DBH), age, stem height, and eccentricity at breast height. It does not appear that a practical field technique could be devised for the rapid estimation of average stem eccentricity in western hemlock.

Characterizing and discriminating the shape of asbestos particles

The lengths and widths of approximately 1000 particles from each of four asbestos samples, two nonfibrous amphiboles, and one talc-serpentine sample were measured utilizing the SEM. The asbestos samples are commercially available and include chrysotile from Quebec, chrysotile from California, amosite from South Africa, and crocidolite from South Africa. The tremolite and talc-serpentine are from New York, and the riebeckite is from California. Beneficiation, including milling of amosite, crocidolite, and tremolite and air classifications of the two chrysotile samples, was done under commercial conditions; the riebeckite was milled in the laboratory. For comparison, the same measurements were made on the California chrysotile using TEM. Shape characterizations of the samples are compared using regression techniques. The usefulness of the various shape definitions including length, width, and aspect ratio (length/width) in characterizing and discriminating between samples is explored and evaluated. Significant results include: (i) Frequency distribution of log length, log width, and log aspect ratio show very apparent differences between asbestos and nonasbestos populations. (ii) Dimensional differences and accurate classification according to dimensions are enhanced by regressing log width and/or log aspect ratio against log length. (iii) Discriminant function analysis is able to quantify the distinction between asbestos and nonasbestos particle dimensions such that over 95% of the population assignments are correct. (iv) Log width is a more efficient classifier than log aspect ratio using either linear regression of discriminant function analysis for these particular samples. (v) The choice of instrumentation, i.e., TEM vs SEM, may affect the sample characterization. (vi) Quantitative descriptions of the dimensions of small particles may be related to the habit of the mineral and the structure of the mineral groups to which the particles belong. However, such mineralogical distinctions are probably not valid for particles whose longest dimension is less than about 1 μm.

Ruffed Grouse Drumming Site Characteristics in Ohio

Physical, site, and vegetational characteristics associated with logs used by male ruffed grouse (Bonasa umbellus monticola) were analyzed to identify occupancy parameters. Perennial activity centers contained nearly 3 times as much brushland and heavily cut woodland as transient centers. Density of shrubs and small trees was greater (P < 0.05) around logs showing continuous use and those with recent use than around logs that had been abandoned and those sporadically used. Mean occupancy length of logs in perennial centers was 16.5 months, longer (P < 0.01) than for logs in transient centers (5 = 10.9 months). The drumming log appeared relatively unimportant in the selection process. J. WILDL. MANAGE. 43(2):324-333 Courtship behavior of male ruffed grouse includes selection, usually for life, of forested areas ranging from 4 to 12 or more hectares (Palmer 1963, Gullion 1967). These areas have been commonly termed activity centers (Gullion 1967:88, Lewis et al. 1968, Porath and Vohs 1972). Within activity centers, an object or objects, usually a log, on the forest floor are selected for drumming. These sites serve as the focal point of spring courtship activity. Physical characteristics of the drumming platform are generally not considered important (Gullion 1967:95, Boag and Sumanik 1969:626). Density, size, canopy coverage, and type of vegetation immediately around the log are considered important (Palmer 1963, Boag and Sumanik 1969, Boag 1976). The importance of drumming log location relative to topography is unclear. In Missouri (Lewis et al. 1968:25) and Indiana (Muehrcke and Kirkpatrick 1970:183), male grouse preferred logs at higher elevations. Studies in Iowa (Porath and Vohs 1972) and Alberta (Boag and Sumanik 1969), made little mention of location relative to topography. Importance of general cover types in which logs are located is unclear, perhaps due to differing vegetative conditions over the range of ruffed grouse. In New York, Bump et al. (1947:280) reported that drumming logs usually were found in woodland cover and associated with conifers, where possible. In Wisconsin, Dorney (1959) found that conifers, and northern hardwoods were used less than aspen-birch, swamp hardwoods, and lowland brush types. Gullion and Marshall (1968:137) reported that grouse in Minnesota survived best in the hardwood-brush type devoid of conifers. Traditional use of certain sites has been reported, but the specific important qualities have not been identified (Palmer 1963:663, Gullion 1967:95). In Ohio, some habitat qualities influencing use of particular drumming sites were unclear. To our knowledge no attempt has been made to compare the physical and vegetative characteristics of activity centers and drumming logs receiving traditional or sporadic use. Also, the use associated durations of occupanI Deceased. 324 J. Wildl. Manage. 43(2):1979 This content downloaded from 157.55.39.132 on Thu, 15 Sep 2016 04:54:05 UTC All use subject to http://about.jstor.org/terms RUFFED GROUSE DRUMMING SITES IN OHIO Stoll et al. 325 cy by male grouse have not been assessed. From 1969 to 1977 we attempted to identify factors important in traditional use by ruffed grouse in Ohio by comparing habitat parameters associated with activity centers and logs receiving traditional or sporadic use. We gratefully acknowledge C. Nixon, J. Davis, C. McKibben, J. Ely, M. Moser, R. Donohoe, and K. Laub for constructive suggestions and field assistance. This paper is a contribution from Federal Aid in Wildlife Restoration Project, Ohio W105-R.

A Reason for Pleomerism

Pleomerism, the increase in vertebral number with maximum recorded length for species within a family, may be explained for fish by hydrodynamic considerations. A model is developed that suggests that the upper limits of the slope of the relation between log vertebral number and log length should be 0.43 in laminar flow and 0.35 in turbulent flow. These slopes are compared with those of previous studies only with difficulty because (1) those values were for predictive rather than functional regressions, (2) the slope will depend on the range in length of various species across temperature zones, and (3) no distinction was made between structural and locomotor vertebrae. Variations in shape also complicate the relation between vertebral count and length, there are latitudinal factors involved, and maximum length is probably only a weak correlate of the length at which natural selection may be concentrated. When these factors are considered, it is to be expected that observations would provide only a rough approximation to theory.The theory underlying the model is also used to derive a formula for the stride length of fish motion that is then compared with empirical results. Key words: vertebrae counts, body size, locomotion, hydrodynamic equations, mathematical model, stride length

Length and weight relationships of Acartia clausi from Narragansett Bay, R.I. 1

Changes in the cephalothorax length and dry weight of Formalin‐preserved copepodite and adult Acartia clausi were followed from 12 March–1 June 1976 and naupliar weights and lengths determined for one sample. Preservation in Formalin caused a significant loss of dry weight, carbon, and nitrogen in adult females, mostly during the first 24 h, but did not significantly affect the C:N ratio or the cephalothorax length of the animals.Length and weight were inversely related to seawater temperature at the time of sampling. As the animals became older this relationship was increasingly affected by their past temperature history. Separate linear relationships between log length and log weight were observed for the nauplii, the CIs, the CII–CVs, and the adults, making it possible to estimate the weight of individual stages from measurements of length.Animals collected on the same day from different stations sometimes showed significant differences in weight for a given length. Such differences could be more clearly expressed by calculation of a condition factor relating weight to the cube of cephalothorax length. The differences in the condition factor appeared to be related to food availability and such differences may be even more apparent when weights of live animals are examined.

Observations on the biology of the perch, Perca fluviatilis, in the River Stour, Dorset

SUMMARY. Opercular bones from 323 perch from the River Stour were used for age and back‐calculated growth determinations. Annuli were formed during May at the beginning of the growth period. Growth was minimal from October to April. Female perch grew faster than males, and the growth rates of both sexes were higher than those observed in most other European waters. Spawning occurred during late April and early May; male gonads began development in August and had attained their maximum weight in September, but the ovaries developed gradually from August until April. Immature perch had an annual cycle of condition with a maximum in June‐July and a minimum in December‐January. The condition of mature males and females was affected by the gonad cycle. The fecundity of Stour perch is expressed by the formula: log egg number = 2.40 log length (mm) ‐ 1.34.Approximately 25% of males were mature at age I and all were mature at age II, whereas most females did not spawn until age III. Ephemeroptera nymphs and minnow fry constituted the bulk of the diet of 0‐group perch; Ephemeroptera nymphs, minnow fry and Corixidae were the most numerous items in I group perch, whereas older perch contained Corixidae and a wider range of fish prey species, although minnows were the most numerous of these.

Firm, patient, and process variables associated with length of stay in four diseases.

Factors associated with length of stay in three London teaching hospitals during 1972 and 1975 were examined in patients treated for myocardial infarction, cerebrovascular disease, inguinal hernia without obstruction, and gall stones. Statistical analyses were carried out with multiple regressions on log lengths of stay.Increased length of stay was associated with infection in all four groups and with the seriousness of operative procedures in all but patients with cerebrovascular disease. Although age was a significant variable in patients with hernias and gall stones, it had relatively little practical effect on length of stay. Other significant variables in at least one disease were obesity, number of abnormalities in blood chemistry, administration of parenteral fluids or oxygen, or use of monitoring devices, and whether chest radiography was carried out, blood electrolytes and urea were measured, or anticoagulants were used. Patients with cerebrovascular disease who were not discharged to their own homes stayed on average more than two and a half times longer than other patients.Between a third and a half of the variance was explained by these variables and the variation among firms. The method described is reproducible in other hospital settings, and the study shows that much new information could be available routinely without mounting expensive field trials.

Metric growth of the uterus in digenetic trematodes (author's transl)

1. The length of the uterus of Dicrocoelium dendriticum, Pleurogenoides medians and Fasciola hepatica at different stages of development is correlated with the corrected size of the body (parallel length x breadth). 2. The data plotted in a log-scale show for all three species a sigmoid curve with linear middle section. 3. The function y = ax + ac(xw - x)3 + b(y = log length of the uterus, x = log length of the body, xw = log length of the body at the turning point) fits very well to the data obtained from Dicrocoelium dendriticum. The constants a, ac and b were determined numerically. The function is valid also for Pleurogenoides medians and Fasciola hepatica but with other constants. 4. The linear middle section of the sigmoid curve may be interpreted by allometric growth. During this phase of development the uterus is tubelike. 5. During the earliest stages of development the uterus forms a solid cord of cells (three-dimensional growth) and grows slower than in a later stage after formation of a cell-free interior (two-dimensional growth). 6. The latest phases of development are characterized by a small increase in length of the uterus due to the three-dimensional dilatation by the produced eggs. 7. The computed function is considered as a modification of the law of allometric growth Y = B . Xa, respectively y = ax + b (log Y = y, log X = x).

Use of Girth Measurement for Estimating Weight of Mountain Goats

Regression formulas show close relationships between weight and linear measurements of mountain goats (Oreamnos americanus) captured in the Sapphire Mountains of Montana. Residual mean squares were used to compare six equations correlating weight and linear measurements. The most dependable estimates are (1) log weight = 1.2574 (log length + log girth) 2.1531, and (2) weight = 0.0011 (length X girth2) + 11.5 (measurements in English system). These formulas appear to estimate weight accurately regardless of sex or age. Girth should be recorded regularly in future studies of North American ungulates to permit calculation of similar formulas for other species. J. WILDL. MANAGE. 39(4):705-708 The mountain goat has been the subject of relatively few wildlife studies, largely due to the inaccessibility of its habitat. Very few of these wildlife studies have employed any capture methods; those which did generally were associated with mountain goat transplant operations (Cooney 1946, McDowell 1949, P-R Job Prog. Rep., Proj. 5-D-7, Montana Fish Game Dept., Helena, Stockstad 1959, Rogers 1960, Charles 1961, Wadkins 1967, P-R Job Prog. Rep., Proj. W66-R-6, Washington Dept. Game, Olympia), and measurements seldom were taken. Whole weights of both live and dead animals were recorded in Montana (Casebeer et al. 1950, Brandborg 1955, Lentfer 1955, Foss 1962) and in Alaska (Klein 1953); hog-dressed weights were compared with weights of live mountain goats in Montana (Lentfer 1955). Since linear measurements are much easier to take than whole weights, the objective of this paper is to provide an accurate method for estimating mountain goat weights from body measurements. Similar weigh estimation formulas have been used for domestic livestock (Manning and Will ams 1950, Ross 1955, 1958) and for Afric n game animals (McCulloch and Talbot 1965, Talbot and McCulloch 1965, Freeman and King 1969), but not for North American game animals. Suitable regression equations for other big game species would permit reliable whole weight estimates from field measurements. We thank G. D. Maclean, P. M. Smith, and J. T. Watkins for assisting the senior author in the trapping program and C. Smith, Montana Fish and Game Department, for providing advice and supplies. We also are indebted to N. A. Slade, Museum of Natural History, University of Kansas, for statistical advice and to R. S. Hoffman, Museum of Natural History, University of Kansas, for reviewing the manuscript. This study was supported by the National Rifle Association, Theodore Roosevelt Memorial Fund, Watkins Fund of the University of Kansas, National Science Foundation, National Aeronautics and Space Administration, Montana Fish and Game Department, American Forest Institute, and University of Kansas Department of Systematics and Ecology. ' Present address: Biology Department, Indiana University Northwest, 3400 Broadway, Gary 46408. 2 Present address: UMC 37, Utah State University Computer Center, Logan 84322 J. Wildl. Manage. 39 (4):1975 705 This content downloaded from 157.55.39.70 on Tue, 06 Sep 2016 05:25:37 UTC All use subject to http://about.jstor.org/terms 706 ESTIMATING MOUNTAIN GOAT WEIGHTS * Rideout and Worthen Table 1. Residual mean square values of six weight estimation formulas for the mountain goat. EquaResidual tion mean number Formula square (1) W = 5.2458 G 95.5 105.526 (2) W = 4.2394 L 118.1 114.201 (3) W = 0.0609 LG 19.7 47.572 (4) W = 0.0011 LG2 + 11.5 43.337 (5) log W = 1.2574 (log L + log G) 2.1531 42.264 (6) log W = 0.8243 (log L + 2 log G) 2.0248 46.725 MATERIALS AND METHODS Mountain goats were captured in a pen trap in the Sapphire Mountains of Montana during the period 1971-73 (Rideout 1974a, b) for instrumentation in a radiotelemetry study of mountain goat movements (Rideout 1973, 1974b). Linear measurements, in inches, were obtained with a flexible steel tape, and weights were taken with a Hanson spring scale with 200-pound capacity and recorded to the nearest pound. Measurements were taken of 27 goats captured from June to November. Total handling time, during which the animals were marked, measured, and released, was 30-45 minutes. The mountain goats used in this study were taken from one herd and included a fairly complete cross-section of the population with regard to both sex and age. The measurements considered in this paper include (1) total length (L), measured from the tip of the nose to the tip of the tail along body contours, (2) girth (G), measured around the chest directly behind the forelegs, and (3) whole weight (W). Linear regression techniques (Sokal and Rohlf 1969) were used for weight estimation formulas. Calculations were carried out with the Honeywell 635 computer at the University of Kansas with programs written primarily by the junior author. Six equations were compared for best estimates of the weight by examining the residual mean square values (unexplained sums of squares /degrees of freedom). In the case of log transformed values, Y values were con180 -

Body Length, Head Circumference, and Weight of Bovine Fetuses: Prediction of Gestational Age

Ninety fetuses from 82 pregnant uteri from Red Danish and Holstein cows were collected at a slaughterhouse. Fetal weights, body length, and head circumference were measured. Correlations were linear between log weight and log length, log weight and log head circumference, and log body length and log head circumference. From these relationships a method of calculating fetal age was derived.

Observations on the age, growth, reproduction and food of the roach Rutilus rutilus (L.) in two rivers in southern England

Scales and opercular bones from 632 roach from the River Stour were used for age and back‐calculated growth determinations. The scales had clearer inner annuli but operculars clearer outer annuli in fish more than nine years old. The annuli were laid in late May or early June at the beginning of the growth period. Growth was minimal between November and April. Roach from both rivers grow faster than those in most other European waters. Female roach grow faster than males; River Frome roach faster than those from the Stour. Spawning occurred in May and elaboration of gonads between September and May. Immature roach have an annual cycle in condition with a maximum in June and a minimum in early Spring. The condition of mature females is affected by the gonad cycle. The fecundity of Stour roach is represented by the formula: log egg number=4.43 log length (mm)—1.69. Approximately half of the Stour males attained sexual maturity at age III and most of the rest by age IV. Half of the females were mature at age IV and the remainder by age V. Both brood success and growth rate varied from year to year but independently of one another. Most Stour roach ate aquatic insect larvae and molluscs but algae were more frequent in the diet of larger fish.

A rapid method for estimating longitudinal growth stresses in logs

A method of rapidly determining the longitudinal growth stress present on the surface of logs and standing trees is described. Application of the technique will enable detailed examination of stress present about the circumference and along the length of trees and logs. In addition it will enable comparisons to be made between trees, as well as monitoring changes occurring in a particular log as the result of treatment to reduce stress. Finally, its use will enable the selection of low stressed trees for genetic studies and propagation trials.

RELATIONS AMONGST VARIOUS LINEAR MEASUREMENTS AND WEIGHT FOR BLACK RHINOCEROSES IN KENYA

SUMMARYRecords of black rhinoceroses obtained from different areas of Kenya suggest a very close relationship between body weight and length and chest girth. The best regressions are: log weight on log length+log girth, and weight on length x girth2. The square of the correlation coefficient in both cases is more than 0.98, and the relations appear to be independent of habitat and sex. In contrast the two sexes show marked differences in the relation between front and back horn length with the males tending to grow relatively longer front horns. Attempts to predict the size of the animal and the length of its horns from the spoor were less successful.

OXYGEN CONSUMPTION IN DIAPTOMUS

The oxygen consumption of fed and unfed Diaptomus siciloides, D. oregonensis, D. leptopus, and D. clavipes was measured at five different temperatures using a micro‐Winkler technique. Regression relationships between log oxygen uptake and each of the following independent variables, temperature, log length, and log weight, as well as the combinations of temperature and length and of temperature and weight, were examined for the four species mentioned and Diaptomus arcticus and Mixodiaptomus laciniatus. The simple regression of log oxygen consumption on log dry weight at the five temperatures and the multiple regression of log oxygen consumption on temperature and log dry weight gave close approximations to the experimental means.