601 



position before cytoplasmic division can ensue. Cell fig. 6 contains 

 three nuclei united in series. Complete disjunction has not yet taken 

 place between the original daughter nuclei, but a cell membrane is 

 discernible beyond the point of nuclear contact. The daughter 

 nucleus to the left is again suffering direct division. Here the divi- 

 sion is in vertical planes, and the nuclei are metachromatic. In cell 

 fig. 7 a very chromatic nucleus, with coarsely granular reticulum 

 and two nucleoli located at opposite poles, is at the initial stage of 

 amitosis. It will be observed that between certain cells (e. g. 2 and 3, 

 5 and 6, and 6 and 7) there is a considerable space, between others 

 (e. g. 1 and 2, and 3 and 4) tHe space is small or absent, cell borders 

 being here indicated apparently by a single membrane. On the basis 

 of the evidence from figs. 1 and 6, cells separated simply by a mem- 

 brane are interpreted as recent daughter cells. 



Figures 8 to 12 are selected cells from another section of the 

 vasa efferentia. In 8 cleavage is inaugurated at the lower border, 

 and progresses obliquely along a path marked by a more chromatic 

 line. Figure 10 illustrates the same points, except that there the 

 plane of fission extends horizontally from left to right. The daughter 

 nuclei here will have to undergo more considerable change of position 

 or shape than in fig. 8. Figure 9 represents a final stage in a type 

 where the plane of division passes in such a fashion (conceivably a 

 short spiral) as to produce two stout and blunt cresents frequently 

 rotated so as to fit together more or less completely along their con- 

 cave faces. This type will be more full}^ described under subsequent 

 more typical illustrations. 



It is of importance to note at this point that the nuclei may be 

 either vesicular or deeply chromatic both at the initial and the final 

 stages of amitosis (compare figs. 8 and 9 with 7, 6 and 1), and thatthe 

 plane of division may be either horizontal or vertical; or it may be 

 oblique and approximate one or the other position. In fig. 11 of the 

 daughter nuclei still in some degree of union one stains faintly, the 

 other deeply. Figure 12 represents a late stage in which the daughter 

 nuclei are still in contact, but on either side of this point a cytoplas- 

 mic cleft has appeared in completion of the amitotic process. 



Figures 13 to 15 are three selected cells from still another section 

 of the epididymis lined with cuboidal epithelium. The first shoAvs 

 the point of contact between two daughter nuclei, represented by the 

 darker circular area in the larger nucleus. Figure 14 illustrates a not 



