1907.] 



Mitosis in Proliferating Epithelium. 



375 



no division or constriction can be recognised. It will be seen that the 

 chromosomes in figs. 3 and 4 are on the equator of the spindle. In fig. 3 



Fig. 3.— Reduction Mitosis in Proliferating Epithelium of Babbit's Ear. 



the number of pairs is 14 ; in other mitotic forms of the same type it was 

 found to vary from 14 to 18. A glance at the heterotype mitosis from the 

 testis of the rabbit (fig. 4), in which the number of gemini or pairs of 

 chromosomes which could be counted was found to vary from 14 to 18, 

 shows the essential morphological identity of the synaptic form occurring 

 in the proliferating epithelium of the rabbit's ear (fig. 3) with the first 

 maiotic mitosis in the testis of the same animal (fig. 4). In both forms the 



Fig. 4. — Heterotype Mitosis in 

 Testis of Rabbit. 



Fig. 5. — Post-synaptic Mitosis in 

 Proliferating Epithelium of Rabbit's Ear. 



