No. 2.] 



THE SEA-URCHIN EGG. 



461 



exactly, I think, to Boveri's " centrosome " with its " Central- 

 korn" or "centriole" ("centrosphere" with its "centrosome" in 

 Strasburger's terminology). The granules now rapidly increase 

 in number, and thus give rise to a central group lying in the 

 centrosphere which at the same time increases in size. As 







Fig. VIII. — Late anaphases. (50 minutes.) 



A . Daughter-chromosomes at the extreme limit of the spindle in contact with the centrosphere. 

 Enlargement of the latter. Degeneration of the spindle-fibres. [</. Phototype 8.] 



B. The chromosomal vesicles lying partly in the centrosphere. \cf. Phototype 9.] 



f 



the granules increase in number they are found to be connected 

 by delicate threads, forming a close reticulum, and with the 

 highest powers the granules seem to be nothing more than 

 nodal points in the network (Text-fig. V). The granules mean- 

 while change their staining power, taking the haematoxylin 

 very feebly and staining red with Bordeaux or Congo red. 



