No. I .] SPERM A TOGENESIS OF BA TRA CHOSEPS. 3 1 



begun to reform and after it has fairly entered its stage of 

 growth. For characteristic figures illustrating the endochro- 

 matic granules see Figs. 2, 9, 21, 26, 57-62, 121. 



The chromoplasts are generally rounded in outline and well 

 defined. When insufficiently differentiated and overstained 

 they frequently appear to be star-shaped and very irregular, 

 but this is merely an effect of the overstaining. While the 

 form is always rounded, it is not always globular, but, on the 

 contrary, oblong or beaded, especially in places where we 

 expect a division of the chromoplast. In the earliest stages of 

 the polymorphous nuclei the chromoplast is generally oblong 

 or consists of two distinct beads (Figs. 1-3). It lies then iso- 

 lated in a vacuole, only surrounded by linin threads radiating 

 from it in every direction. At a later stage the chromoplast 

 is seen to be in more or less intimate connection with the 

 leaders on which the chromioles are suspended. To begin 

 with this connection is very slight (Fig. 3), but later on it 

 becomes more intimate, and leaders with chromioles are seen 

 to start out in all directions, radiating from the chromoplast 

 like the radii from the center of a circle. When there is more 

 than one chromoplast, leaders connect with all. 



Some chromoplasts, however, may be connected with more 

 leaders than others (Figs. 8, 9). In the last resting stages, 

 when all the leaders have formed, it wilf be seen that all of 

 them connect with the chromoplasts in such a way that if, 

 for instance, one of the chromoplasts is connected with only 

 four leaders, the other is found to be connected with the bal- 

 ance, i.e., eight ; there are always as many leaders as there will 

 be chromosomes. The chromoplasts appear thus to attract the 

 leaders, and my opinion is that in this manner the chromosomes 

 are formed. We can follow the chromoplasts with certainty 

 up to the end of the anaphase. In the bouquet stage, where 

 the spireme segments begin to separate from each other, it will 

 be seen that this separation is caused by a division of the chro- 

 moplasts into several parts. In the perfect bouquet stage we 

 thus find that two or more spireme segments are held together 

 by a single chromoplast (Figs. 14-16). The ultimate result 

 of this division is undoubtedly to so divide the chromoplast 



