CLASSIFICATION OF THE CYCLE OF THE SEMINIFEROUS EPITHELIUM IN THE COMMON TREE SHREW (TUPAIA-GLIS)

The classification of the cycle of the seminiferous epithelium was car ried out in the common tree shrew (Tupaia glis). The tree shrew captur ed in Thailand were fixed with Bouin's fixative, embedded in paraffin wax, and stained with PAS-hematoxylin. The cycle was classified into t welve stages on the basis of the acrosomal changes of spermatids. Rela tive frequencies of stages from I to XII were 11.9, 7.2, 8.9, 22.5, 12 .9, 9.7, 8.0, 5.9, 4.0, 3.2, 2.9, and 3.6%, respectively. Different st ages did not appear in a cross-sectioned tubule as did in primates. Th e head of matured spermatid was discoidal in shape and different from that of primates and rodents. Spermatogenesis of the common tree shrew is different from that of primates and rodents according to its morph ological features.