SEGMENTATION. 235 



All these facts, to my mind, point to the view that these 

 cone-like bodies do not disappear, but form the basis for the new 

 nuclei. Possibly the body visible in each cone in the later 

 stage, was the commencement of this new nucleus. Gotte 1 has 

 figured structures somewhat similar to these bodies, but I hardly 

 understand either his figure or his account sufficiently clearly 

 to be able to pronounce upon the identity of the two. In case 

 they are identical, Gotte gives a very different explanation of 

 them from my own 2 . 



A second of my results, which points to a series of inter- 

 mediate steps between division and solution of the nucleus, is 

 the distribution in time of the peculiar cone-like bodies. These 

 are present in fair abundance at an early period of segmentation, 

 when there are but few nuclei either in the blastoderm or the 

 yolk. But at later periods, when there are both more nuclei, 

 especially in the yolk, and they are also increasing in numbers 

 more rapidly than before, no bodies of this kind are to be seen. 

 This fact becomes the more striking from the lobate appearance 

 of the later nuclei of the yolk, an appearance which exactly 

 suits the hypothesis of the rapid budding off of fresh nuclei. 



The observations of R. Hertwig 3 on the gemmation of Podo- 

 plirya gemmipara, support my interpretation of the knobbed 

 condition of the nuclei. Hertwig finds (p. 47) that 



The horse-shoe shaped nucleus grows out into numerous anastomosing 

 projections. Over the free ends of the projections little knobs appear on 

 the surface of the body, into which the lengthening ends of the processes of 

 the nucleus grow up. Here they bend themselves into a horse-shoe form. 

 The newly-formed nucleus then separates from the original nucleus, and 

 afterwards the bud containing it from the body. 



From the peculiar arrangement of the net-work of lines of 

 the yolk around these knobbed nuclei, it is reasonable to con- 

 clude that interchange of material between the protoplasm of 



1 Entwickelungsgeschite der Unke, PI. i. fig. 18. 



2 As I before mentioned, Strasburger (Zellbilditng u. Zelltheilung) has represented 

 bodies precisely similar to those I have described, which appear during the seg- 

 mentation in the egg of Pliallusia mainmillata as well as similar figures observed by 

 Butschli in eggs of Cucullamis elegans and Blatla Germanica. The figures in this 

 monograph are the only ones I have seen, which are identical with my own. 



3 Morphologischcs Jahrbitch, Bd. i. pp. 46, 47. 



1 6 2 



