222 GERM-CELL CYCLE IN ANIMALS 



or they may remain separate and later become scat- 

 tered. Paulcke (1900) also noted nuclear-like bodies 

 near the oocyte nucleus of the queen bee, and Mar- 

 shall (1907) has likewise found them in Polistes 

 pallipes. In this species the nuclear-like bodies 

 form a single layer around the nucleus ; later they 

 come to lie near the periphery of the oocyte and 

 finally disappear. Loewenthal (1888) has described 

 what appears to be chromatin in the cytoplasm of 

 the egg of the cat, and an elimination of chromatin 

 was noted by van Bambeke (1893) in the ovarian 

 egg of Scorpcena scrofa. In none of these species, 

 however, have keimbahn-determinants been dis- 

 covered. 



According to Buchner (1910) the "besondere 

 Korper" in the egg of Sagitta, and in fact keimbahn- 

 determinants in most other animals are of a chromid- 

 ial nature, representing the tropho-chromatin de- 

 manded by the binuclearity hypothesis. The term 

 chromidia was introduced by R. Hertwig in 1902 and 

 applied to certain chromatin strands and granules 

 of nuclear origin in the cytoplasm of Actinosphcerium. 

 Goldschmidt (1904) transferred the chromidia hy- 

 pothesis to the tissue cells of Ascaris. Since then 

 chromidia have been described in the cells of many 

 animals, including both somatic and germ cells. 

 Thus far the group of zoologists that favor the 

 chromidia idea have not received very extensive 

 backing, but the fact remains that chromatin 

 particles are in some cases cast out of the nuclei in 

 the oocytes of certain animals and continue to exist 



