590 VEKA DANCHAKOFF 



If application of too strong solutions is followed by breaking 

 up of the nucleus in a few parts, each of these parts exerts an 

 attraction on the basophilic substance of the cytoplasm and 

 the latter accumulates around them, 



4. The development of chromatin within the nucleus in nor- 

 mally fertilized eggs as well as in parthenogenesis proceeds in the 

 form of small spots or bodies, intimately connected with the 

 membrane. The close relation between the true chromatin 

 bodies within the nucleus and the basophilic chromatic substance 

 in the cytoplasm is easily traced. The chromatin of the nucleus 

 may develop either in the form of innumerable small granules, 

 appearing invariably at the inner surface of the nuclear mem- 

 brane or in the form of larger bodies, which are similar to nucleoli. 

 Chromatin develops in a similar way in parts of the nucleus aftqr 

 application of too strong solutions. 



5. The union of male and female pronuclei can proceed dif- 

 ferently. The male pronucleus may join the female pronucleus 

 in an achromatic stage; in other cases it adds to the female pro- 

 nucleus during copulation considerable amounts of chromatin 

 either in unchanged form, or in the form of already differentiated 

 chromosomes. 



6. The chromosomes are differentiated from the chromatin 

 network of the nucleus. The chromatin bodies, which first ap- 

 pear at the inner surface of the nuclear membrane, contribute to 

 the formation of the chromatin network; they give offshoots, 

 which soon join together. 



7. The differentiation of the spindle seems to be connected 

 with the bipolar radiations and with the migration of plastosomes 

 or archoplasm. The threads of the spindle are attracted by the 

 chromosomes and attach themselves firmly to them. They grow 

 into the substance of the nucleus and push the chromosomes to 

 the equator. Centrosomes at the first cleavage mitosis appear 

 as a dense network in the center of the bipolar radiations or 

 astrospheres, in which network accumulations of basophilic 

 granules may be seen. 



8. The chromosomes undergo vesicular transformation during 

 telophase, become achromatic and join together into an achro- 



