Taxonomic Considerations Research Articles

Taxonomic Considerations for Carboniferous Coalified Compression Equisetalean Strobili

Taxonomic Considerations for Carboniferous Coalified Compression Equisetalean Strobili

Primary and Secondary Skin Leishmaniasis in Experimental Rodent Hosts

Pathological observations are described from experimental infections of Syrian hamsters, nude mice and bank voles with different Leishmania strains isolated from travellers returning to Germany from endemic areas. The main purpose of the paper was to demonstrate the changing patterns of parasite predilection sites within appropriate experimental animals. Despite the occasionally-occurring episodes of altered predilection sites the principal organotropic behaviour of given Leishmania strain was remarkably constant in in vivo passages. Here a genetic background seems evident which justified a legal use of such host related properties in taxonomic considerations. It was noted that humans appear to be poor indicators of the micro-ecological abilities of Leishmania spp.

Unusual polar lipids of Micrococcus radiodurans strain Sark.

The polar lipids of Micrococcus radiodurans strain Sark appear to be unique in that common bacterial phospholipids such as phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and phosphatidylinositol are absent. Of the 13 polar lipids detected, 5 contain phosphorus and carbohydrate, 4 contain carbohydrate and no phosphorus, and 1 contains phosphorus as well as sulfur. None of the polar lipids contain free choline or amino groups and none are sensitive to phospholipases C or D. Of eight selected polar lipids tested, all were found to be labile to milk alkali, suggesting the presence of ester linkages. It is suggested that the unusual lipid profile of M. radiodurans strain Sark may be useful in taxonomic considerations.

Helminth parasites of squirrels (Sciuridae) in Saskatchewan

During the period March 1976 to November 1977, 377 mammals of the family Sciuridae (Rodentia) were collected in Saskatchewan and examined for helminths. Species and numbers of each were as follows: Spermophilus richardsonii (Sabine), 209; Spermophilus franklinii (Sabine), 46; Spermophilus tridecemlineatus (Mitchill), 31; Tamiasciurus hudsonicus (A. H. Howell), 64; Glaucomys sabrinus (Shaw), 12; Eutamias minimus (J. A. Allen), 11; and Marmota monax (Erxleben), 4.Ten species of cestodes, 2 species of trematodes, 11 species of nematodes, and 1 acanthocephalan were represented in the collections made. New host records and (or) geographic range extensions were indicated for 10 species of helminths.In addition to taxonomic considerations of the helminths, attention has been given to parasite–host relationships involving ground squirrels. In general, male Spermophilus spp. were significantly more commonly infected than were females, and older squirrels were significantly more commonly infected than were younger ones. However, adult squirrels did not have significantly more worms than did juveniles.

Semiotic systems and knowledge representation

This paper deals with cognitive processes and knowledge representation. The starting point is an analysis of an object, treated as a relational system and its representation. The formalism developed is especially convenient to capture the problems of observability and change. After these considerations, a formal theory of semiotics is outlined, allowing a new development and unified treatments (within the paradigm of fuzzy set theory) of such topics as structure of signs and their configurations (spatial and temporal), i.e. formal representations of situations and events; structure of the cognitive representations of signs, leading to the construction of a language of semantics; and structure of verbal representations of objects (their verbal copies), the latter analysed by means of the methods of mathematical linguistics, leading, among other things, to the foundations of formal text theory. As regards verbal copies, the main stress is put on cognitive constraints on descriptions imposed by the limitations of knowledge and/or observability, and constraints imposed by the language used. The properties of verbal copies can also be fruitfully related to theories of perception and memory. The set of interrelated theories presented here, and introduced for the first time by the author, allows for a compact and unified way of treating the topics which were traditionally considered separately, as various parts of psychology, philosophy or logic. As regards formal semiotics, as sketched here, it goes far beyond the notions of Peirce, leading to a system richer than taxonomical considerations, allowing for the development of semiotic theory.

BIOLOGY AND SPECIATION OF ECHINOCOCCUS GRANULOSUS†

SUMMARY: The biology of Echinococcus granulosus is reviewed and attention given to recent advances in our understanding of this parasite. In particular, studies on the parasite within the definitive host, an area which has been neglected in the past, have demonstrated our lack of knowledge concerning the cytodifferentiation of the adult cestode during its development, and events which take place at the host‐parasite interface. An important aspect of the biology of the parasite is the nature of its reproductive mechanism which involves both sexual and asexual multiplication. Such a reproductive pattern is considered to be the major factor responsible for the appearance of subspecific variants of E. granulosus adapted both to domestic and wild animal life cycles.The speciation pattern that exists within the species E. granulosus is extremely complex. Numerous subspecific variants have been described and attempts to unravel the situation taxonomically have resulted in controversy. Criteria used in the recognition of specific and subspecific varieties have all too often over emphasised morphological details, while the presence of biological differences between varieties or strains has been neglected. Recently, however, comparative studies on various strains have demonstrated the value of considering epidemiological, developmental and biochemical criteria. The significance of these criteria beyond pure taxonomic considerations is becoming increasingly evident, and future studies may help to explain differences in reproductive potential and host specificity.In Australia, hydatid disease is of considerable economic and public health significance, yet there has been little work undertaken on the speciation of the parasite. The potential for the existence of speciation differences within Australia is greater than in some other countries, since geographical separation may act as a factor in the selection of subspecific strains. Of particular importance is whether the existence of wild‐animal cycles is dependent upon the maintenance of domestic life cycles in Australia.

Capnocytophaga: new genus of gram-negative gliding bacteria. I. General characteristics, taxonomic considerations and significance.

The characteristics of gliding bacteria isolated from both healthy and diseased sites in the oral cavity are, summarized and the taxonomic position of the bacteria discussed. Uniform attirubtes of the fusiform isolates include gliding motility, strictly fermentative metabolism dependent on the presence of CO2 (or HCO3-), under either anaerobic or aerobic conditions, presence of benzidine-reactive components, and the production of acetic and succinic acids as the major or sole, acidic, metabolic and products. Given the guanine and cytosine content of DNA, their gliding motility, and the ability of many strains to attack polysaccharide a relationship to the cytophagus is suggested. This relationship, along with the CO2-dependent growth is recognized by the generic name Capnocytophaga given them. Many of the isolates are grouped into three species C. ochracea, C. Sputigena, and C. gingivalis, separated on the basis of morphological and physiological traits.

Aspects of speciation in Echinococcus granulosus

Studies on the speciation of Echinococcus granulosus in Great Britain have demonstrated the value of considering epidemiological, developmental and biochemical criteria. The significance of these criteria beyond pure taxonomic considerations is stressed, and the particular potential of isoelectric focusing in such studies is emphasized.

Approaches to the Study of the Behavior of Sharks

Many kinds of sharks are dangerous and apparently unpredictable predators whose behavior is virtually unknown. This is because they are difficult both to maintain in captivity and to observe in the field. However, the purpose of this paper is to review the behavioral information on sharks and, more importantly, to suggest approaches which will accelerate progress in understanding the activities of these animals. Shark behavior has been investigated within the methodological frameworks of both comparative psychology and ethology. Thus the underlying philosophies of these disciplines are briefly discussed. Six approaches for investigating the activities of sharks are presented. Approach I involved intuitive studies drawing upon natural history notes and fisheries statistics, and is typified by Springer (1967). This work set the stage for future quantitative research. Approach II is also intuitive. Here, as typified by Klausewitz (1962), inferences about behavior and ecology are drawn from morphologic and taxonomic considerations. Results appear to be useful in only the broadest of applications. Approach III, an ethological approach we term “structure of behavior,” rests upon direct observation of behavior. The basic rationale underlying this technique, including examples of field and laboratory studies with sharks, is given. While we are at a beginning stage in the ethology of sharks, this approach appears to hold great promise. Approach IV, the study of activity rhythms in sharks, is reviewed. Little is known about such rhythms, which represent short-term temporal activity. Practically nothing is known about long-term activity, i.e., behavioral ontogeny. In Approach V psychological studies of learning are reviewed with emphasis on habituation, operant and classical conditioning in sharks. It is concluded that learning probably plays an important role in the lives of sharks and that they are clearly not the stupid, blindly swimming creatures of folklore. In Approach VI studies of sensory physiology using behavioral techniques are briefly discussed. Results led to the conclusion that sharks are well adapted to detect and respond appropriately to a wide variety of environmental stimuli. Though the difficulties are real and many, the paper ends on an optimistic note, and it is felt that continued effort will unquestionably lead to a significant increase in our understanding of these fascinating animals.

Morphological characters, relative to distribution, and taxonomic considerations of the genus Climacium in North America

A quantitative and qualitative analysis of Climacium americanum and C. dendroides in North America confirms that these two taxa are distinct, although there is limited morphological intergradation in the region of the Great Lakes eastward to the coast. Climacium americanum has branch leaf upper cell length-to-width ratios of 3–7(8): 1, branch leaf auricles generally larger, stem leaf apices acuminate, and capsules symmetric, 3.0–6.0 mm long; while C. dendroides has branch leaf upper cell length to width ratios of (6)7–13:1, branch leaf auricles generally smaller, stem leaf apices obtuse and apiculate, and capsules usually asymmetric, 1.5–4.0 mm long. Climacium americanum is endemic to southeastern North America, while C. dendroides is western and boreal in distribution. It is hypothesized that the endemic C. americanum arose in isolation from the circumboreal C. dendroides. Upon retreat of Pleistocene glaciers, geographical intermingling of the two species resulted in limited morphological intergradation in southeastern Canada and northeastern United States. Climacium kindbergii is considered to be taxonomically synonymous with C. americanum, while C. novae-seelandiae is regarded as taxonomically synonymous with C. dendroides. Climacium japonicum is a distinct species characterized by a few large teeth on the abaxial surface of the costa of branch leaves.

Isolation and Characterization of Aquaspirillum fasciculus sp. nov., a Rod-shaped, Nitrogen-Fixing Bacterium Having Unusual Flagella

In 1971, Strength and Krieg reported the isolation of a gram-negative freshwater rod which exhibited bipolar flagellar fascicles clearly visible by dark-field microscopy. The flagellar fascicles exhibited helical wave propagation, basal bending, and an ability to coil up like springs. Despite the flagellar activity, the cells were apparently unable to swim freely. Such organisms appeared to be similar morphologically to an organism previously described by Houwink in 1953 and Jarosch in 1969. The present report describes a reliable isolation method for such organisms based on the use of L-proline and semisolid agar. Upon isolation, the organisms grew in flocs, from which a highly viscous matrix could be separated by high-speed centrifugation. After many transfers, the growth gradually became homogeneous and turbid, and the viscous substance could no longer be demonstrated. Under certain conditions of growth, steady straight-line motility could be observed and photographed within viscous flocs. Straight-line, free-swimming motility occurred in viscous suspensions of cells prepared by homogenization of flocs. In 8- to 12-h-old cultures in the nonviscous homogeneous condition, some cells could swim slowly in irregular, circular paths; other could move about on surfaces. When the viscosity of the medium was increased, nearly every cell could swim freely and steadily in straight paths. A viscosity of 200 centipoise was optimal for strain XI, whereas 10 centipoise was optimal for strains X and XII. These results suggest that the organisms may be highly adapted to life within viscous flocs. The organism exhibited nitrogenase activity when tested by methods developed by Döbereiner and her colleagues for “Spirillum” lipoferum; Aquaspirillum peregrinum also was found to possess nitrogenase activity. Investigation of the physiology and deoxyribonucleic acid base composition of strains X, XI, and XII has indicated that even though the organisms are straight rods, they are probably members of the genus Aquaspirillum. Important taxonomic considerations include: Coccoid body or “microcyst” formation, possession of a “polar membrane” similar to that occurring in certain spirilla, bipolar tufts of flagella, a strictly respiratory metabolism, inability to attack carbohydrates, positive catalase and oxidase reactions, and a deoxyribonucleic acid base composition of 62 to 65 mol% guanine plus cytosine. The organisms were assigned to a new species, Aquaspirillum fasciculus, and the type strain was deposited with the American Type Culture Collection under the number 27740.

Feeding Relationships among Species of Notropis (Pisces: Cyprinidae) in a Wisconsin Stream

The relationship between spatial preference and diet in four species of the genus Notropis (Pisces: Cyprinidae) was investigated in Roxbury Creek, a small stream in southern Wisconsin. Characteristic spatial distributions for each species were determined from frequency of catch in unbaited minnow traps set at varying heights and locations in the pools of the stream. Data for the year 1966—67 indicate that two species, Notropis atherinoides and N. spilopterus are common in midwater. Notropis dorsalis is most frequently found near the bottom and shows a strong preference for the upstream edge of pools Notropis stramineus is also found most often near the bottom but within the pools themselves. The spatial distributions of aquatic invertebrates, the major prey of Notropis in the pools of Roxbury Creek, were also investigated. Data gathered from drift and bottom samples taken in eight sampling periods during 1970—71 suggest a separation between the relatively sedentary bottom fauna, composed of oligochaetes, isopods, several genera of chironomids, tipulids, and trichopterans; and the drift fauna, composed of copepods, chironomids of the subfamily Orthocladiinae, ephemeropterans, and terrestrial anthropods. Certain genera, including the ubiquitous Gammarus were found commonly in both drift and benthic samples. Indices of similarity between pool benthos and drift ranged between 7% and 59%. Data on food habits of Notropis gathered from stomach content analysis of fishes collected over the same period indicate that 73% of the invertebrate genera present are utilized by Notropis species in Roxbury Creek. Considerable overlap exists in the invertebrate genera chosen by the four species (69%—84%), and strong overall correlations between species are found in the importance of various orders of aquatic invertebrates in the diet. Differences in food habits relate principally to differences in space utilization. Midwater species tend to feed on drifting chironomids, copepods, terrestrials, and other animals found in the water column. Bottom—dwelling fishes feed on benthic genera of chironomids, tipulids, oligochaetes, and other organisms found commonly in pool substrates. It is concluded that spatial rather than taxonomic considerations are the chief determinants of prey selection in these four species, and that this pattern of resource subdivision acts to reduce competition in sympatric, syntopic populations of these fishes. Data from other Wisconsin Streams, from aquarium observations, and from literature review suggest that multispecific assemblages of mutually responsive species like the ones in Roxbury Creek are common in Notropis.

ON THE TYPIFICATION OF MERTENSIA WILLD. NON ROTH (GLEICHENIACEAE) WITH NOTES ON STICHERUS PRESL AND HICRIOPTERIS PRESL

SummaryPichi Sermolli (1972) has cited Mertensia dichotoma (Thunb. ex Murray) Willd. as lectotype of Mertensia Willd. In so doing he has ignored the taxonomic facts on which earlier citation of M. truncata Willd. as type of Mertensia considered as a subgeneric name was based. The facts are briefly re‐stated, and the selection of M. truncata as type of the genus defended. Brief notes are added on the genera Sticherus and Hicriopteris of Presl. A general objection is made to nomenclatural decisions made without reference to taxonomic considerations.

The biosystematics, chemotaxonomy, and ecology of Claytonia lanceolata in western Washington

The morphology, biochemistry, and phenology of Claytonia lanceolata Pursh (Portulacaceae) was examined in western Washington and an analysis was made of associated vegetation and soils. Contrary to earlier taxonomic considerations, the results of this study do not support specific or subspecific separation of the two color forms (yellow and white). Two significantly different populations were revealed, however, based on size characters. These populations were also correlated with different community types and to a lesser extent soils, although detailed analysis of the chemical and physical properties of the A horizon showed intrapopulational variation to be at least as great as that between populations. Finally, the question of ecotypic distinction of the two population types is discussed.

Nosema juli n. sp., a microsporidian parasite in the millipede Diploiulus londinensis caeruleocinctus (Wood) (Diplopoda: Julidae).

The morphology and life stages of a new species of Microsporidia, Nosema juli, in the millipede, Diploiulus londinensis caeruleocinctus (Wood), are described. The initial site of infection appears to be in the fat body, with subsequent development in muscles and connective tissues. Some pathological characteristics and taxonomic considerations are indicated. This is believed to be the first report of a microsporidian infecting an arthropod in the class Diplopoda.

Fatty acid distribution in triglycerides of the tree hyrax

1. 1. Analysis of triglycerides of the tree hyrax ( Dendrohyrax arboreus) showed that 79 per cent of the total palmitic acid was esterified to the secondary alcoholic group of the glycerol. 2. 2. This is unusual intramolecular disposition resembles that of elephant triglycerides and supports current taxonomic considerations that hyraxes and elephants are distantly related.

Taxonomic Considerations of the Family Nitrobacteraceae Buchanan: Requests for Opinions

A revision of the family Nitrobacteraceae Buchanan is proposed. It is requested that the Judicial Commission issue an Opinion placing the generic names Nitrosocystis Winogradsky, Nitrosogloea Winogradsky, and Nitrocystis Winogradsky on the list of rejected names as nomina dubia. Organisms currently placed in these genera are to be transferred to other genera or their names are to be regarded as later, subjective synonyms of other names or as nomina dubia. Thus Nitrosocystis oceanus Watson will be transferred to Nitrosococcus as Nitrosococcus oceanus (Watson) comb. nov.; Nitrosocystis coccoides Starkey is to be regarded as a synonym of Nitrosococcus nitrosus (Migula) Buchanan, Nitrosomonas monocella Nelson, a synonym of Nitrosomonas europaea Winogradsky, Nitrosospira antaretica Winogradsky and Winogradsky, a synonym of Nitrosospira briensis Winogradsky and Winogradsky, and Nitrocystis sarcinoides Winogradsky, Nitrocystis micropunctata (Winogradsky) Winogradsky, and Nitrobacter agilis Nelson as later, subjective synonyms of Nitrobacter winogradskyi Winslow et al.; Nitrosogloea merismoides Winogradsky, Nitrosogloea membranacea Winogradsky, Nitrosogloea schizobacteroides Winogradsky, and Nitrosocystis javanensis (Winogradsky) Starkey are to be regarded as nomina dubia. The Judicial Commission is requested, therefore, to issue an Opinion placing these nomina dubia (names whose application is uncertain) on the list of rejected names. The type strain of Nitrosolobus multiformis, ATCC 25196, is described. The following strains are described and are here designated as type strains: Nitrosococcus oceanus ATCC 19707, Nitrococcus mobilis ATCC 25380, and Nitrospina gracilis ATCC 25379. The following strains are described and are here designated as neotypes: Nitrosomonas europaea ATCC 25978, Nitrosospira briensis ATCC 25961, and Nitrobacter winogradskyi ATCC 25391.

Morphological and Chemical Correlations in the Cladonia chlorophaea Complex

Measurements of granules from within the podetial cups of different chemical variants of the Cladonia chlorophaea complex in North Carolina show clear correlation between granule size and certain chemical characters. The results support the view that the replacement of cryptochlorophaeic acid by grayanic acid in this group is taxonomically more significant than the presence or absence of fumarprotocetraric acid. In the species tested, the soredia of C. conista are the smallest, those of C. perlomera and C. grayi are intermediate, and those of C. cryptochlorophaea are the largest. The Cladonia chlorophaea group was treated by Sandstede (1931) as including two species-C. chlorophaea (Flirke) Spreng., containing fumarprotocetraric acid and consequently distinguished by a bitter taste, and C. grayi Merr. ex Sandst., lacking fumarprotocetraric acid and consequently with a mild taste. Asahina (1940) discovered grayanic acid, cryptochlorophaeic acid, and merochlorophaeic acid in this group and divided the complex into four species: Cladonia grayi, C. cryptochlorophaea Asah., and C. merochlo?rophaea Asah. are characterized by the presence of grayanic acid, cryptochlorophaeic acid, and merochlorophaeic acid, respectively, while C. chlorophaea is considered to have fumarprotocetraric acid only. Within each of the first three species, the presence or absence of fumarprotocetraric acid is generally ignored from taxonomic considerations, but Asahina treated such fumarprotocetraric acid variants as forms. Although these four species are the most common ones of the chlorophaea group, many other variants have been recorded (Ahti, 1966; Culberson & Kristinsson, 1969). The morphologic variability has generally been considered to be the same within all the chemically different races in the complex. Ahti (1966), however, indicated some morphological differences between some of the plants called C. merochlorophaea and those of the other chemical species, and Krog (1968) claimed that the rangiformic acid variant in Alaska has a characteristic morphology. Wetherbee (1969) has demonstrated substrate specificity in some of the chemical species in Michigan. The present paper deals with the morphology and distribution of the chemical variants of the C. chlorophaea group in North Carolina. Since a preliminary survey indicated that there was a significant difference in the size of the soredia in the podetial cups between some of the chemical variants, a large-scale survey was made. Other 1 This study was supported by grant GB-6041X from the National Science Foundation. I thank Dr. William Louis Culberson for his interest in this work and for linguistic corrections and Dr. Chicita F. Culberson for her advice on the identification of the lichen substances. 2 Department of Botany, Duke University, Durham, North Carolina 27706. Present address: NMttlirugripasafnit Q Akureyri, P.O. Box 580, Akureyri, Iceland. This content downloaded from 157.55.39.153 on Mon, 19 Sep 2016 04:46:55 UTC All use subject to http://about.jstor.org/terms 14 THE BRYOLOGIST [Volume 74 100 Cladonia grayi PD+ s ---C. grayi PD?. C. cryptochlorophaea PD+ . .... .. ........ C. cryptochlorophaea PDo/ .... C)' I 0 100 200 300p LLI N A

Subgeneric Division of Japanese Graminicolous Helminthosporia in Relation to Systematics of Host Plant

A taxonomic consideration of some species was carried out to divide into subgenera Euhelminthosporium and Cylindro-Helminthosporium. Conidia of Helminthosporium brizae and H. dematioideum were observed to germinate by the production of lateral germ tubes from the basal cell. The mode of germination of conidia was employed as a key character in separating the two subgenera in Helminthosporium, agreeing to Luttrell's view, and both of the species were preferably placed in the subgenus Cylindro-Helminthosporium. In addition, H. zonatum also was included in Cylindro-Helminthosporium as based on a photograph attached to the original description by Ikata and Yoshida.From a review of the literature and the writer's observations on Helminthosporia parasitic on Gramineae in Japan, 19 species are enumerated as members of subgenus Euhelminthosporium, and 16 species for Cylindro-Helminthosporium. Only H. arundinis described by Nisikado and by Sawada is excluded because it needs further study to permit a satisfactory disposition.The host plants of respective subgenera of Helminthosporium clearly fall into two different groups of gramineaceous subfamilies sensu Stebbins and Crampton: i. e., Euhelminthosporium spp. are found to be parasitic on the grasses belonging to either subfamily Oryzoideae, Eragrostoideae or Panicoideae, while only one species, H. sorokinianum Sacc. ex Sorok., occurs on members of Festucoideae. On the other hand, all of the 16 Cylindro-Helminthosporium species occur on grasses of subfamily Festucoideae. It may be inferred that the grasses which are north temperate in distribution as represented by Festucoideae are infected primarily by the species of Cylindro-Helminthosporium, whereas grasses with centers of distribution in the tropics and subtropics, such as Oryzoideae and Panicoideae, are infected primarily by the members of Euhelminthosporium.This relation apparently holds good in the other foreign species of Helminthosporium, though some exceptions have to be admitted. One of the exceptions is that H. giganteum Heald et Wolf occurs on tropical grasses though it belongs to subgenus Cylindro-Helminthosporium. It is interesting to note that H. giganteum has a very wide host range, as does H. sorokinianum, an exceptional species in Euhelminthosporium.

A TAXONOMIC STUDY OF LABIATAE AND RELATED GENERA

SummaryExtensive comparative anatomical and morphological observations have been made on 400 species (138 genera) of Labiatae and Verbenaceae sensu lato. Two computational analyses, very different and calling for different coded interpretations of the data, gave essentially similar classifications. These analyses and subsequent taxonomic consideration result in an arrangement which does not reflect the present family boundary. Four of Bentham's eight tribes of Labiatae (Ocimoideae, Satureieae p.p., Monardeae, Nepeteae) seem distinctly different from the rest which come closer to Verbenaceae. Of ten subfamilies and tribes sampled, only Ajugoideae and Verbenoideae emerge intact. In terms of this sample, forty‐seven genera gain support but twenty‐five are heterogeneous in that species form groups not conforming with present generic boundaries.