lO CALIFORNIA ACADEMY OF SCIENCES. 



plasmic nodes the cytospheres are seen to arrange them- 

 selves regularly. 



In the majority of the new cytoplasmic micronuclei I 

 have not been able to see the nucleoli, but I think it is 

 safe to say that they are frequently present. As to the 

 relationship of the nucleoli found in the micronuclei with 

 that of the macronuclei I cannot say anything with cer- 

 tainty from observation. I believe, however, that the 

 nucleolus of the macronucleus dissolves sooner or later, 

 and that the nuclei found in the micronuclei are really 

 new elements not directly derived from the macronucleus. 

 Generally, however, the nucleoli remain conspicuously, 

 though of diminished size, long after the macronuclei 

 have all diffused themselves through the cytoplasm. In 

 the newly formed spores more or less numerous highly 

 refractive bodies are seen, greatly resembling the inter- 

 nucleolar bodies and probably identical with them. 



Since the above was written and presented for publica- 

 tion, I have received the paper by Dr. L. Rhumbler on 

 *'Die Enstehung und Bedeutung der Binnenkorper," 

 and I am pleased to say that I find in his explanation of 

 the structure and action of the nucleoli a satisfactory so- 

 lution of the morphological importance and nature of 

 these interesting bodies. I have observed in Spermato- 

 bium all the three stages he refers to, the liquid, the vis- 

 cicous and the solid stage of the nucleolar contents, the 

 above described highly refractive intranucleolar bodies 

 belonging to the latter. The nucleoli of Truncatulina 

 lobatula, as delineated by him (fig. 30, Taf. xviii), is al- 

 most exactly identical with some of the nucleoli observed 

 by me. Judging from my own observations, the more 

 solid parts of the nucleoli could form directly from the 

 liquid part, or at least independently of the viscous part. 

 Dr. Rhumbler's theory that the nucleoli are not organic 



