Bulbous Part Research Articles

Morphology of ctenostome bryozoans: 7. Hislopia, Echinella andTimwoodiellina.

Ctenostome bryozoans are a small group of gymnolaemates comprising less than 400 recent species. They are paraphyletic and ctenostome-grade ancestors gave rise to Cheilostomata, the most dominant and speciose taxon of Bryozoa in the present day. Investigations into ctenostomes are important for reconstructing character evolution among Gymnolaemata. As a continuation of studies on a morphological series of ctenostome bryozoans, we herein investigate six species of hislopiids, a small clade of threegenera occurring in freshwater habitats. The general morphology of all species is similar in having primarily uniserial chains of encrusting zooids, which are mostly oval to ellipsoid and have a flattened frontobasal axis. Hislopia prolixa and Echinella placoides often have more slender zooids with a higher frontobasal axis. Apertures of hislopiids are quadrangular, lined by a thickened cuticle. Apertural spines are present in various lengths in E. placoides, Hislopia lacustris and Hislopia corderoi. The remaining cuticle is rather thin except at lateral areas, close to the pore-plates which are prominent in hislopiids because of abundant special and limiting cells. All species except H. corderoi and Timwoodiellina natans have a prominent collar obstructing the vestibulum, whereas the latter two species instead have an 'external collar' as cuticular, outer folds projecting over the aperture. Hislopiid lophophores carry eight, or more commonly 12-18 tentacles. The digestive tract is distinguished by an often highly elongated esophagus and/or cardia, with the latter always having a prominent bulbous part in the form of a proventriculus-or gizzard in E. placoides. The caecum is extensive in all species. In Hislopia the intestine is characteristically two-chambered with a proximal and distal part before entering an anal tube of various length. The latter is present in all species except T. natans and terminates in mid-lophophoral area. Oocytes in E. placoides are large and macrolecithal indicating brooding and the production of lecithotrophic larvae. Hislopia species produce small, oligolecithal ones, which suggests zygote spawning and planktotrophy. In general, the morphology is similar among the different hislopiids with characters of the gut aiding in delineating the genera Echinella and Timwoodiellina.

Water hyacinth (Eichhornia crassipes) as an oviposition site for the disease transmitting snail Indoplanorbis exustus (Deshayes 1833) (Gastropoda: Planorbidae): implications in snail management

The water hyacinth (Eichhornia crassipes) is an invasive species in freshwater ecosystems with potential to alter habitat features and macroinvertebrate community composition. Many freshwater snails are associated with the water hyacinth for food and refuge. In the present study, an assessment of the water hyacinth as an oviposition site of the freshwater snail Indoplanorbis exustus was conducted through evaluation of the field collected plants. Apparently, the bulbous part of the water hyacinth was preferred over the leaves and the stems in terms of the egg capsules and eggs per egg capsule oviposited by I. exustus. A logistic regression indicated significant differences in the preferred oviposition sites by the snail. Owing to the invasion of the water hyacinth, the oviposition and further colonization by the snail I. exustus may be facilitated

DEMOGRAPHIC STUDY AND THE MANAGEMENT OF URETHRAL STRICTURE IN H. ADAM MALIK GENERAL HOSPITAL

Objective: This study aims to describe the demographic data and clinical characteristics of patient 
 with urethral stricture in Adam Malik Hospital. Material & Methods: This research was a retrospectively designed descriptive study, with a consecutive sampling method. Data such as age, clinical symptoms, length and locations of stricture, and the type of operation conducted, were obtained from medical records from May 2013 to June 2017. All subjects had given consent that their medical records can be involved in this research. Results: 60 urethral stricture cases were found, with trauma as a major cause with a percentage of 58.3% of the cases. While the iatrogenic cause (combining post cystoscopy and post operation) contributed only 15% of the total cases. The mean age for subjects was 34.07 ± 2.044 and most of them complained about urinary retention and difficulty in initiating micturition (hesitancy). In contrast, the symptoms that were rarely revealed by subjects were weak stream and pain during micturition, with total of only 3.4% of the cases. A large part of the urethral stricture cases originated from the Bulbous part (30%) with the stricture mean length is 18.32 ± 1.944, and the part where stricture would least likely happen is the membranous and the prostatic part (8.3%). Urethrotomy (Sachse) was the favorite surgical technique used by urologists to manage urethral strictures. Conclusion: This research showed that the characteristics of patients who were diagnosed having urethral stricture in Indonesia are similar with the results from other studies conducted before. It also showed even though urethroplasty has vast advantages compared to the conventional urethrotomy (Sachse), it was still underappreciated by the surgeons. 

The one-stage balloon dilatation with stone extraction for a combination of short urethral stricture and urethral stone in men

Introduction. The literature highlights isolated studies examining approaches to the treatment of patients with a combination of stones and urethral stricture. In this regard, the problem of creating optimal tactics for managing such patients remains relevant.Purpose of the study. To analyze of own experience in treating patients with a combination of stricture and urethral stone using balloon dilation with urethral stone extraction.Materials and methods. The study included 7 men with short urethral stricture and stone, who underwent balloon dilation with urethral stone extraction. The age of patients ranged from 47 to 65 years (median - 52 years). The length of the urethral stricture ranged from 3 to 10 mm (median - 7 mm). The stricture in 2 (28.6%) cases was localized in the penile part of the urethra and 5 (71.4%) in the bulbous part. An etiology of urethral strictures: traumatic - in 2 (42.9%) patients, inflammatory - in 1 (14.3%) of cases, idiopathic - in 4 (57.1%) of cases. All patients had 1 urethral stone. The sizes of the stone ranged from 4 to 9 mm (median - 6 mm).Results. The operation time ranged from 11 to 19 min (median - 13 min). No patient had any intraoperative complications. UTIs was observed in the early postoperative period in 1 patient. The duration of postoperative hospital stay ranged from 1 to 5 days (median - 3 days). Postoperative follow-up ranged from 3 to 24 months (median - 14 months). Only 1 (14.3%) patient had a recurrence of urethral stricture 18 months after treatment. Thus, the overall treatment success in this group of patients was 85.7% (6/7).Conclusion. We used this conjunction approach when combined stricture and urethral stone in men for the first time in the world. It seems quite promising given the results.

First Report of Clavinema mariae (Nematoda: Philometridae) in Cultured Rockfish, Sebastes schlegeli, in Cheonsuman (Bay), the Republic of Korea

In July 2012, philometrid nematodes were discovered in cultured rockfish (Sebastes schlegeli) in Cheonsuman (Bay), the Republic of Korea. The nematodes were detected in the epithelial tissues of the rockfish and were identified as Clavinema mariae based on morphological studies using light and scanning electron microscopy. They revealed the characteristics same as previously identified C. mariae, notably having a long body with narrow posterior half, no caudal projection, a cylindrical-shaped esophagus, a well-developed anterior bulbous part of the esophagus, cephalic papillae, and a dorsal esophageal gland. This is the first confirmation of C. mariae infection in rockfish in Korea.

Histological Studies on Penis of the Boar (Sus scrofa domesticus)

Histological features confirmed that penis of boar was a fibroelastic organ with a corpus cavernosum and corpus spongiosum. The caverns were surrounded by connective tissue trabeculae with smooth muscle cells. Helicine arteries with epithelioid smooth muscle cells in tunica intima were in the corpus cavernosum penis. Cavernous spaces of both corpus cavernosum and spongiosum were lined by single layer of endothelium. Tip of the penis was intimately covered by visceral layer of the prepuce which was lined by stratified squamous epithelium. Large solitary lymphatic nodules were seen in internal layer of prepuce. The penile urethra was enclosed in corpus spongiosum. Urethra mucosa was thrown into longitudinal folds with transitional epithelium from external urethral orifice to bulbous part. Average thickness of transitional epithelium at root, body and glans was 27.3 ± 1.42 µm, 58.5 ± 1.42 µm and 78 ± 1.42 µm respectively.

Diversity in antioxidant properties and mineral contents of Allium paradoxum in the Hyrcanian forests, Northern Iran

Khodadadi S, Nejadsattari T, Naqinezhad A, Ebrahimzadeh MA. 2015. Diversity in antioxidant properties and mineralcontents of Allium paradoxum in the Hyrcanian forests, Northern Iran. Biodiversitas 16: 281-287. The knowledge about variation ofantioxidant properties from local medicinal plant can be achieved by investigating all natural habitats of it. To reach this goal, acomprehensive survey on eight populations of Allium paradoxum (M. B.) G. Don, was conducted in the Hyrcanian forests. A.paradoxum (Amaryllidaceae) is a perennial, local plant, native to the northern Iran. Different parts of it, is largely used in foodpreparation and traditional medicine. Plants were collected randomly from different altitudes and forest sites of Iranian northernprovinces ranging from west to east (Guilan, Mazandaran and Golestan Provinces). Samples were divided into aerial and bulbous parts.The antioxidant activities of the extracts were investigated with 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and reducing power assays.Total flavonoid content was determined by a colorimetric aluminum chloride method. The highest antioxidant activities and flavonoidcontents in A. paradoxum were related to Varaki and Zarinabad sites (Mazandaran province) with relatively higher humidity, in thecentral part of the Hyrcanian area and in altitudinal range between 462-860 m asl. The content of total phenolics in the extracts wasdetermined according to the Folin-Ciocalteu reagent method, and calculated as gallic acid equivalents (GAE). With respect to totalphenolic contents, aerial parts of plants of Jahannama, the lowest elevation site (Golestan province), had the highest amount. Elementalcomposition (Fe++, Mn++) and total sulphur were also determined using Atomic Absorption Spectroscopy and digestion method,respectively. Higher contents of two elements, particularly Fe, and total sulphur can be found in bulbous part of Zarinabad and Kiasarpopulations (Mazandaran province) compared to other sites. The results of the current study indicated that there is a remarkable andsignificant variation of antioxidant activities among different studied populations of A. paradoxum in the Hyrcanian forests.

CICATRIZATION AND REGENERATION

Introduction. The cicatrix as the local site of a sclerosis, replaces wound defect or focus of a necrosis. Lead to cicatrization various type of a trauma, including operational, and also some of diseases. Cicatrization quite often leads to stricture and other complications.Materials and methods. The methodology of stimulation of regeneration for reduction of intensity of cicatrization of the damaged tissues is shown on the example of the patient from a stricture urethra.Results. In 5 months after an endoscopic urethrotomy of a stricture of bulbous part of urethra of 3 mm and the developed recurrence - the stricture of bigger length - 5 mm the repeated endoscopic urethrotomy was carried out. In 5 months after carrying out a repeated endoscopic urethrotomy and the beginning of the complex treatment directed on stimulation of regeneration and prevention of formation of cicatricial tissue according to a control urethrography the bulbous part of urethra was passable.Conclusion. Complex stimulation of regeneration taking into account a role of immune system in this process, on an equal basis with purpose of proteolytic ferment preparations, can be used for reduction of expressiveness of sclerosis of the damaged tissues.

A new subfamily and species of Ostracoda (Cylindroleberididae, Myodocopa) from the Chatham Rise (New Zealand)

The second species of the genus, Macroasteropteron chathamensis sp. nov. is described in the present paper. It was collected from 1000 m depth during the New Zealand national biodiversity programme Ocean Survey 20/20 to the Chatham Rise and the Challenger Plateau. To accommodate this genus, a new subfamily Macroasteropteroninae is described herein. It is defined by the following autapomorphies: locking system on the shell; very small second segment on the second antenna (bearing no dorsal bristles); square shaped third and fourth segments on the same appendage; absence of dorsal bristles on the third segment of the male clasping organ; reverse position of the alpha and beta bristles on the maxillula; almost square shaped skirt on the sixth limb; and a bulbous terminal part of the seventh limb, which, in addition, does not have any bell-bearing bristles. A key to the four subfamilies of Cylindroleberididae is provided.

Clonal propagation of Zephyranthes grandiflora using bulbs as explants

Zephyr lily (Zephyranthes grandiflora), an important ornamental plant has been micropropagated in vitro after controlling microbial contamination by a pretreatment with 0.2 % Bavistin and 0.1 % Pantomycin for 4 h before final sterilization with 0.1 % mercuric chloride. In 67 % of the sterile cultures, 11 shoots on average were regenerated directly from basal half of bulb scales in Murashige and Skoog (MS) medium containing 3 % sucrose and 2 mg dm−3 benzylaminopurine (BAP). Shoots emerged in bunches on a basal achlorophyllous bulbous part. Combination of 2 mg dm−3 BAP with 1 mg dm−3 gibberellic acid (GA3) enhanced shoot growth. Stout roots (maximum of 5–6 per shoot) were developed in presence of 1 mg dm−3 indole-3-butyric acid (IBA). Micro-bulbs showed potential of regeneration and could be used as secondary explants. The morphologically identical plants derived by in vitro propagation were genetically identical as shown by PCR based ISSR marker analysis of genomic DNA.

Two new species of hexabothriid monogeneans from the ginzame Chimaera phantasma and shortspine spurdog Squalus mitsukurii

Descriptions are given for two new species of hexabothriid monogeneans, one collected from the gills of shortspine spurdog Squalus mitsukurii and the other from the gills of the ginzame Chimaera phantasma in Sagami Bay on the Pacific coast of Japan. Squalonchocotyle mitsukurii n. sp. from Squalus mitsukurii can be distinguished from Squalonchocotyle squali MacCallum, 1931, the most closely related species, by the inwardly curved vagina. Callorhynchocotyle sagamiensis n. sp. from Chimaera phantasma can be distinguished from all the known species of Callorhynchocotyle Suriano & Incorvaia, 1982 by the structure of the cirrus; in the new species, the cirrus is entirely muscular with a widened opening, while in the four known species it comprises a tubular proximal part and a bulbous distal part.

The ultrastructure and reproduction of Amphiamblys capitellides (Microspora, Metchnikovellidae), a parasite of the gregarine Ancora sagittata (Apicomplexa, Lecudinidae), with redescription of the species and comments on the taxonomy

The ultrastructural cytology and reproduction of the hyperparasitic microsporidium Amphiamblys capitellides (Caullery and Mesnil, 1897) is described. Merogonial reproduction was not observed. The sporogony comprises two sequences: a sac-bound sporogony in close contact with the cytoplasm of the host and a free sporogony in parasitophorous vacuoles. The free sporogony, which probably precedes the sac-bound, yields a small number of rounded spores. The sac-bound sporogony is polysporoblastic, generating two rows of elongated spores. All stages have isolated nuclei. Both spore types have an extrusion apparatus of the metchnikovellidean type, with a polar sac devoid of anchoring disc, a polar filament with one manubroid and one bulbous part, and a posterior semicircular membrane fold enclosing rounded or tubular structures. Hosts are gregarines of the species Ancora sagittata living in the intestine of polychaetes of the genus Capitella, probably the species Capitella giardi. The cytology, life cycle and classification are discussed. The species is redescribed and the diagnosis of the genus Amphiamblys Caullery and Mesnil, 1914 is emended.

Development of functional dentin incisors after a partial resection of the odontogenic organ of rat incisors

The resection of the labial half of the odontogenic organ of rat incisors resulted in the development of teeth without enamel. Ten out of 26 operated rats developed a functional dentin incisor, i.e. a continuously growing and erupting tooth. These teeth were a little shorter and much thinner than normal incisors. The dentin and pulp presented a normal structure. Periodontal ligament and cement started to develop at the lingual face and gradually all tooth faces were invested by these tissues. The original socket space, to accommodate a thinner tooth, was narrowed by newly formed bone around the inner face of the socket. Eleven rats developed defective dentin incisors; these teeth showed signs of growth, however, their eruption was impaired. The operation failed in five rats. The odontogenic organ of the dentin incisor presented islands of epithelial cells at the labial aspect of a dense mass of mesenchyme cells. These islands, formed by densely packed, dark-staining cells encircling a few pale-staining cells, merged gradually, forming a root sheath and a cervical loop limiting a long apical foramen. The bulk of the bulbous part (apical bud) was absent; thus, there was no differentiation of ameloblasts and of the crown-analogue part of the incisor. The growth and eruptive behaviour of the dentin incisor, similar to that of a normal incisor, indicates that it has to bear a stem cell niche to retain its regenerative capacity. As in the apical bud, this niche is apparently located at the stellate reticulum of the cervical loop. The putative molecular mechanisms related to either the maintenance of the stem cell niche or the differentiation of the enamel organ and the root sheath are discussed. These data and our results, showing the development of a functional dentin incisor, suggest that the root-analogue part of the rodent incisor is an anatomic-physiological entity.

Biomechanical properties of the anterior urethra of the male rabbit--a study using impedance planimetry.

To evaluate the anterior urethra of the male rabbit regarding its luminal cross-sectional area (CSA), CSA distensibility, circumferential tension-strain relation, histology and the collagen content of the tissue. material and methods: Nineteen rabbits were examined with impedance planimetry by distending the urethra at the passage from the spongious to the bulbous part and 1 cm proximally in the bulbous part. Four weeks later, eight rabbits underwent a second examination. After the measurements the urethras were processed for either histology or determination of collagen content. The urethras from six additional rabbits served as controls for histology and collagen content. The CSA and the CSA distensibility were smaller at the distal than the proximal distension site. At both sites the CSA distensibility was high at low luminal pressure loads and decreased with increasing pressure. The circumferential tension-strain plot displayed an exponential relation, with a steeper slope distally than proximally. Repeated biomechanical investigation revealed a significantly increased CSA and a decreased slope of the circumferential tension-strain relation at both distension sites. The biomechanical investigation induced abrasion of the epithelium, extravasation of erythrocytes and separation of the collagen fibres, suggesting oedema of the luminal part of the wall. After 4 weeks the epithelium had changed from transitional to stratified, squamous and often keratinized epithelium and the collagen beneath the epithelium formed a dense network instead of wavy lines as seen in the control urethras. The collagen content was larger at the distal than the proximal distension site. No change in collagen content could be demonstrated between the urethras investigated once or twice with impedance planimetry. The non-linear pressure-CSA, pressure-CSA distensibility and circumferential tension-strain relations found at both distension sites demonstrate that the urethra yields readily at low pressures, thus facilitating flow. At higher pressure loads, the tissue becomes less distensible, a property that protects it against over-distension and damage. Impedance planimetry cannot be used to study before-and-after phenomena as the biomechanical investigation changed both the histology and the biomechanical properties of the rabbit urethra.

Another CT sign of sinonasal polyposis: truncation of the bony middle turbinate.

In order to study the features of sinonasal polyposis (SNP) on CT, 100 consecutive coronal sinus CT examinations done for chronic inflammatory sinonasal disease were reviewed. The CT findings of the 27 fully documented SNPs were analyzed. All our SNPs were bilateral. There was a strong tendency for extensive involvement. Nasal polyps were seen in 22 of 27(81%); bony trabecular deossification in 23 of 27 (85%); widening of infundibulum in 26 of 27 (96%). We discovered a new sign "truncation of the bony middle turbinate", where the bulbous part of bony middle turbinate was missing, in 15 of 26 (58%) of SNP patients without a previous history of middle turbinectomy, 12 of 15(80%) were bilateral. The one SNP patient (1 of 27) with previous middle turbinectomy was not regarded to be real truncation. Truncation of the bony middle turbinate is a characteristic and easily recognizable ancillary sign, and is not seen in other patterns of sinusitis. Together with other features on coronal sinus CT, this adds diagnostic confidence in diagnosing sinonasal polyposis.

A Study on Wave-Free Floating-Body Forms in Heaving Motion

The floating-body forms having two frequencies at which no heaving force is exerted in waves are considered in this paper. It is found by applying Chou's method that the floating-body forms possess the constricted part between the free surface and the bulbous part in the water. Heaving forces of several cylinders with the cross sections of the wave-free forms are calculated by source method and measured in wave-excitation experiments. Both results of the calculation and the experiment confirm that heaving forces vanish at two frequencies.Secondly, investigations are made for a catamaran composed of such cylinders and a vertical body of revolution whose profile is similar to the cross section of one of the cylinders. It is also the case for these bodies to have two wave-free frequencies.

Cell turnover in the odontogenic organ of the rat incisor as visualized by graphic reconstructions following a single injection of 3H-thymidine.

Turnover of cells within the odontogenic organ was studied in three dimensions by preparing serial sections of incisors from young male rats killed at various times following a single intraperitoneal injection of 1 muCi/g body weight of 3H-thymidine. Radioautographs showed that at 1 hour after injection labeled cells were present in all cell layers throughout the entire depth of the odontogenic organ. They were encountered frequently within the inner dental epithelium and stratum intermedium but appeared less abundant within the stellate reticulum and outer dental epithelium. With time, the frequency of labeled cells in each layer declined progressively, and more rapidly at the anterior and labial side of the odontogenic organ than toward its posterior and lingual side. Hence labeled cells were observed over the longest time interval in regions where cell layers were in closest proximity to the opening of the apical foramen, that is, near the apical and cervical loops. By 32 days after injection, numerous labeled cells could still be identified within the outer dental epithelium and stellate reticulum near the apical loop (bulbous part of the odontogenic organ) and the outer dental epithelium near the cervical loops ("U"-shaped part of the odontogenic organ). These findings support the hypothesis that cells originate within the bulbous part of the odontogenic organ and migrate anteriorly through the "U"-shaped and root sheath parts of the odontogenic organ during renewal of the incisor. It appears that individual stem cell compartments may be maintained for surface (outer/inner dental epithelium) and intermediate layers (stellate reticulum/stratum intermedium) in the odontogenic epithelium.

Movement of entire cell populations during renewal of the rat incisor as shown by radoioautography after labeling with 3H-thymidine. The concept of a continuously differentiating cross-sectional segment. (With an appendix on the development of the periodontal ligament).

Renewal of the rat incisor was studied in three dimensions by employing a serial cross-sectioning technique to locate the boundary between labeled and unlabeled cells in the enamel organ and odontoblast layer at various times after a single injection of 3H-thymidine. This boundary, or leading edge of the front of labeling, was graphically illustrated through point-plotting reconstruction of the labial surface of the incisor. At one hour after the injection of 3H-thymidine the front of labeled ameloblasts was located within the presecretory zone related to early predentin secretion. This front formed a "C"-shaped curve stretching across the labial surface of the tooth from the lateral to the mesial cemento-enamel junction. The "C" was open anteriorly and the lateral arm extended almost twice as far incisally as the mesial arm. The edge of the front of labeled odontoblasts was positioned apical to and parallel with this "C"-shaped curve. The morphological appearance of all cells along each respective front was found to be similar. As the fronts of labeled ameloblasts and labeled odontoblasts moved forward with the erupting incisor, the cells along these fronts differentiated simultaneously and subsequently formed enamel and dentin. Throughout this movement the distance between fixed points along the leading edge of the front of labeled ameloblasts, and its positional relationship to the front of labeled odontoblasts, did not change appreciably. This indicated that cells of the tooth were being carried incisally at a uniform speed. It was concluded that renewal in the rat incisor consists of the generation by the bulbous part of the odontogenic organ of epithelial "U"-shaped cross-sectional segments which enclose a core of pulp. As this segment is transported towards the gingival margin, cellular differentiation and subsequent formation of hard tissue is seen to begin at the central labial side of the segment and to progress in a mesial and lateral direction towards the lingual side. In the process, the limits of the enamel organ at the mesial and lateral cemento-enamel junctions are established and the entire circumference of the segment is eventually enclosed by a rim of dentin.

Histological and three dimensional organization of the odontogenic organ in the lower incisor of 100 gram rats.

A three dimensional reconstruction of the epithelial tissue at the apical end of the lower rat incisor was made from serial 1 mum thick cross sections. This tissue formed an elongated structure, called the odontogenic organ, which was composed of a bulbous and a "U"-shaped part. Both parts were joined to one another at the posterior aspect of the apical foramen. The bulbous part of the odontogenic organ was situated at the lingual side of the "U"-shaped part and protruded anteriorly over the pulp. It was formed by cells of the outer dental epithelium and stellate reticulum whose organization suggested that the bulbous part was important in the production of cells for renewal of all the epithelia of the incisor. The "U"-shaped part of the odontogenic organ was apparently derived from the bulbous part and delineated the pulp by forming the lateral, mesial and labial sidewalls around the apical foramen. It was composed of all the epithelial cell types recognizable as precursors to (a) cells of the enamel organ which form the enamel, and (b) Hertwig's epithelial root sheath, a part of the odontogenic organ which induces the formation of dentin on the lingual aspect of the incisor.

Studies of the cutaneous glands and hair follicles of some species of Macropodidae

Histological studies were made on skin samples from wild red kangaroos, Megaleia rufa (Desmarest), grey kangaroos, Macropus canguru (Miiller) syn. M. giganteus and M. major of three colour variants, euros, Macropus robustus Gould, and one swamp wallaby, Protemnodon bicolor (Desmarest). The hair cover was densest in the mid-dorsal region of the body, on the cheeks, and on the shoulders and the thighs. The density decreased ventrally. On the tail the hair follicles were less dense on the ventral than on the dorsal surface. The red kangaroo had the densest hair cover. The thickness of the hair fibres varied inversely in relation to the density of hair cover. Hair follicle grouping on the ventral surface of the tail was characteristic for each species and the hairs there uniformly resembled bristles. Males of all species, except the euro, were found to have consistently thicker skin on the ventral surface of the body but in females the skin was thicker on the back. In the tails of both sexes of all species the skin was thicker on the ventral than on the dorsal side. The thickness of the papillary layer on the ventral surface of the tail was correlated with the size of the animal and it is suggested that it may possibly be used as a measure of age. The complete absence of a reticular layer was noted in the skin of all species of macropods examined. The type and distribution of sweat glands was studied and sex, age, and species differences were demonstrated. Euros were found to have sweat glands with a characteristically bulbous lower part, in addition to the types of sweat glands present in the other species. In males of all species highly convoluted apocrine glands occurred in the breast and axillary regions while in females they were most common in the cloaca-pouch area. The behavioural importance of the secretion of these glands is suggested. Histological differences in the skin of the three colour variants of the grey kangaroo are described and the taxonomic value of skin characteristics is suggested.