The tip of the cat tongue was examined by transmission and scanning electron microscopy. Many filiform papillae were densely distributed over its dorsal surface. At low magnification, all of the filiform papillae were seen to be slightly inclined toward the back. Each filiform papilla had a baso-frontal circular slope and some conical twigs were arranged in a semicircle from the back of the slope. Histologically, the keratinized layer was thickest in the epithelium on the posterior side of filiform papillae. The surface of this area contained abundant pits and hollows. A cornified layer was also observed on the anterior side of filiform papillae, but it was not as thick as on the posterior side of filiform papillae. The cell surface of this area contained faint microridges. The interpapillary epithelium showed little evidence of keratinization, but well-developed microridges were visible on its surface. From these observations, it appears that microridges are lost from the epithelial surface in conjunction with the advance of keratinization.

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The exact age of white-lipped deer Cervus albirostris was determined by counting the annual layers of dental cementum on the first incisor and the first molar. The first annual layer (layer of the winter season) of the first incisor and the first molar of this species was formed during the second winter season after birth. Furthermore we analyzed the deer's age based on tooth replacement, location of cervical lines and the progress of wear on the molar teeth. The age of newborn deer to 2.5-year-olds could be estimated by tooth replacement alone. For 2.5- to 8.5-year-old deer, age could be estimated by the appearance of the lingual and buccal cervical lines of M₁, M₂ and M₃. For deer over the age of 8.5 years, the wear index on the M₁, M₂ and M₃ was an effective method of estimating age.

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The play behaviors in relation to the behavioral development among a group of 15 vampire bats Desmodus rotundus (eight adults and seven young) were observed in captivity. Solitary and social plays occurred mainly in the young. In the solitary plays (exploration), the activities reached the peak at the age of 1 year and decreased gradually to the age of 2 - 3 years. The social plays including chasing, jostling and wrestling appeared largely in young bats. The central role of the social plays was taken by young and subadult males (the ages of 3 to 21 months) . Especially they had favorite play partners. The behaviors of young may contribute to maintain the social stability in this species.

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