ABSTRACT. In order to obtain the basic data to identify the skeletal remains from the archaeological sites, morphological and morphometrical studies were carried out on skulls of living raccoon dogs (35 males and 45 females) and badgers (16 males and 8 females) from Kagoshima Prefecture. Macroscopically, the sexual differences were observed in badgers for the parts of the zygomatic process of the temporal bone and the occipital squama, but were not in raccoon dogs. Among 24 cranial measurements, significant sexual differences were found in five measurement items in raccoon dogs, while 12 items in badgers. Mandibles showed significant sexual differences in both species. Raccoon dogs had significantly larger values than badgers in most of the items concerning length of cranium and most mandibular measurements. The discrimination efficiencies of discriminant formulae between both sexes were lower in raccoon dogs, but higher in badgers, and the efficiencies between both species were obtained 100%. In the regression formulae for estimating skull length, some formulae showed high coefficients of determination in both species. These observations represented interspecific and sexual differences in the skulls of raccoon dogs and badgers. -KEY WORDS: badger, interspecific difference, raccoon dog, sexual dimorphism, skull measurement.

ABSTRACT. To obtain the data required for identification of skeletal remains excavated from archaeological sites, histometrical observations were made in the cross sections of the mid-shaft of humerus, radius, femur and tibia of raccoon dogs (Nyctereutes procyonoides) and badgers (Meles meles) captured in Kagoshima Prefecture. There were interspecific differences between both animals in the breadth, the depth and the area of medullary cavity at the mid-shaft of the bones. In badgers, all measurements were greater in male than in female bones. The thickness and the area of compact bones in male raccoon dogs were larger than those of female. No differences in histological structure could be detected among the bones, but an interspecific difference was found in the shape of osteons; round and constant-sized osteons consisting of 3 to 5 lamellae in raccoon dogs, while round or elliptic osteons varying in size from 3 to 8 lamellae in badgers. The ratios, the osteon areas per unit compact bone areas, were higher in all the bones of raccoon dogs. The short diameters of osteons and the ratios were greater in males in both animals. In females, the short diameter of osteons was smaller, and the number of osteons was larger. The results revealed interspecific differences between both animals and sexual dimorphism in each species. -KEY WORDS: badger, bone histometry, interspecific difference, raccoon dog, sexual dimorphism.J. Vet. Med. Sci. 60(3): 323-326, 1998 in the present study. The animal with the closed epiphyseal lines of long bones was regarded as adult. Two cross sections (1 mm thick) were obtained from each mid-shaft of the bone. The specimens were dehydrated in a graded ethanol series and embedded in Rigorac, a polyester resin to prepare undecalcified ground sections (30 to 40 µm thick). After the ground sections were observed with a light microscope, 9 items shown in Table 1 with their abbreviations were measured with an image analyzer (Nikon COSMOZONE Is) in each section. NO, DO and RO were measured at the anterior, posterior, medial and lateral regions (1 mm 2 each) of the section of each bone. These data were compared between species, sexes or kinds of bones using Student's t-test. RESULTS Morphometrical observations in cross sections:The values obtained in cross sections of the mid-shaft of each Recently, a number of skeletal remains of animals including those belonging to the canid and mustelid species were excavated from archaeological sites in Kyushu [13]. Only a few complete skeletons were found, however, and most discoveries were bone fragments. In such cases, it is difficult to identify species with bones similar in size. This is particularly true for bones of the limbs of raccoon dogs and badgers. Because the mid-shaft is less characteristic in form as compared with the proximal and distal extremities of the limb bones, macroscopic identification of raccoon dogs and badgers is extremely difficult.A large number of histometrical studies were made on the bones of human [2,3,6,17,18], which described...

ABSTRACT. To obtain detailed information about the histological changes occurring in the mouse nipple during the reproductive cycle, we examined and quantified the S-phase of cell by immunohistochemical staining with bromodeoxyuridine (BrdU), and analysed histologically the subepithelial fibrous elements. The nipple markedly increased in size dramatically on days 15-18 of pregnancy. The densities of cells in the epidermis and dermis were very high during the early stages of pregnancy but low during lactation. In the epithelium of the lactiferous sinus, the densities of cells did not differ significantly among stages. The BrdU antibody labeling revealed a number of BrdUpositive cells in the basal layer of the epidermis and epithelium of the lactiferous sinus. The ratios of BrdU-positive cells to total cells in the epidermis and the epithelium of the lactiferous sinus were highest on day 15 and day 10 of pregnancy, respectively. After lactation, however, the ratios were similar to those in the virgin stage. No significant differences were detected in the dermis among all stages. The number of collagen and elastic fibers increased during lactation. These results indicate that cells in the epidermis and lactiferous sinus proliferated actively from day 10 to day 15 of pregnancy. The observation that cellular proliferation in the epithelial system of the nipple was stimulated at the early stage of pregnancy, while the dermis has two growth phases, with cellular proliferation during pregnancy and an increase in extracellular matrix during lacation, suggests that these two phenomena might be regulated by different factors. MATERIALS AND METHODS Animals:The Jcl-ICR strain mice used in this study were bred and maintained as a closed colony in our laboratory. They were all housed in an environmentally controlled airconditioned room (temperature: 23 ± 3°C, humidity: 60 ± 10%, light-dark cycle: 12-12 hr) and given a commercial diet (MF, Oriental Yeast Co., Tokyo) and tap water ad libitum. A total of 33 female mice (80-day-old) were mated with males of the same age, and the day when a vaginal plug was found was determined as day 0 of pregnancy. They were divided into 11 groups; i. e. virgin, days 5, 10, 15 and 18 of pregnancy, days 5, 10, 15 and 20 of lactation, days 5 and 10 of post-weaning. Each group consisted of 3 mice. At the lactating stage, each dam was housed with her 10 pups and separated from the young for 30 min before sampling.Administration of BrdU: BrdU (50 mg/kg b.w., Sigma, MO) was injected intraperitoneally into female mice at each reproductive stage. One hour after the injection, the nipples were excised under sodium pentobarbital anesthesia and fixed with Bouin's solution for 2 hr at room temperature. Mice have 3 pairs of thoracic and 2 pairs of abdominoinguinal nipples, and the first left abdomino-inguinal nipple was examined. The specimens were routinely embedded in paraffin and longitudinal sections 3 µm thick were cut.Immunohistochemical staining: To detect the S-phase cells, BrdU administration and an...

Histological changes in the rat nipple during the reproductive cycle were observed. In virgin and the first half (days 5 and 10) of pregnancy, the nipple had a dull conical shape and the germinative layer of epidermis, thicker than that of the skin surrounding the nipple, deeply ingrew into the dermis in the basal region. From the second half (days 15 and 20) of pregnancy to the post-weaning period, the nipple appeared columnar in shape and many wrinkles were observed in the nipple wall especially during the lactating period. Collagen fibers longitudinally running in the nipple wall mainly comprised the dermis of the nipple and became loose during lactation. Small numbers of elastic fibers running parallel with smooth muscles were also observed in the nipple wall, and these increased in number and thickness from the second half of pregnancy, and most became frizzy structures during lactation. Around the lactiferous sinus, smooth muscle cells were arranged longitudinally but a few muscle cells were seen in a concentric layer, but during the lactating period the sinus was distended and many epithelial folds were observed. Morphometrical analysis indicated that the length of the nipple increased from the second half of pregnancy and reached the maximum on day 15 of lactation, approximately 3.7 times that in the virgin period. The outer diameter of the nipple and thickness of the nipple wall during lactation also reached approximately twice that in virgin. The size of the nipple decreased gradually after weaning. These observations suggest that the histological changes in the rat nipple during the reproductive cycle were mainly characterized by hyperplasia of the epidermis and hypertrophy of connective tissue in the dermis from the second half of pregnancy.