24 RISEN. [Vol. XVII. 



erally being three. There are more chromomeres in the early 

 spireme stages than in the later ones, and as these early ones 

 also are smaller, it appears as if the later chromomeres are the 

 results of the fusion of several smaller ones. In the perfected 

 bouquet stage there are, as a rule, about a dozen chromomeres 

 in each spireme segment (Figs. 15, 121). Those nearest the 

 chromoplasts are larger and possess more chromioles than 

 those more distant. When the chromomeres split there is 

 almost, without exception, six chromioles in each. With the 

 splitting of the spireme segment the chromomeres again lose 

 their identity to a considerable extent, appear smaller, and 

 are more numerous ; the chromioles also are smaller. But 

 these chromomeres fuse again into larger chromomeres, and 

 when in the contraction stage the bretzel-shaped chromosome 

 is formed we find that it possesses twelve chromomeres, each 

 one with six chromioles (Fig. 121 E). The new or daughter- 

 chromosome, which results from the equation division of the 

 bretzel, contains only six chromomeres, each with six chromioles 

 (Fig. 121 /). From this time on the chromomeres gradually 

 lose their identity, and more and more fuse together until at 

 last, at the end of the anaphase, they have become so confluent 

 that no trace of their original form remains. But as soon as 

 the nucleus begins to reconstitute itself the chromomeres at 

 once reappear (Figs. 62, 118). The number of chromioles at 

 this time is uncertain. The following stage of growth of the 

 nucleus is characterized by a greater separation of the chromo- 

 meres (Fig. 119). The typical number of chromomeres in the 

 chromosomes of the spermatocyte is the same as in the chro- 

 mosomes of the auxocyte, or six in each. The exact number 

 of chromomeres which go to make up a chromosome sometimes 

 varies. Thus we now and then find chromosomes with only four 

 chromomeres instead of six, but we may then always expect to 

 find that some other chromosome possesses eight chromomeres, 

 and that in this way the proper number is made up. From the 

 above it will be seen that the chromomeres cannot be considered 

 as permanent organs of the nucleus or more in particular of the 

 chromosome, but that they are merely convenient forms of struc- 

 ture, the object and function of which is to facilitate the hand- 



