No. 3-] THE EGG OF ALLOLOBOPHORA FOETIDA. 137 



we can support our conclusions with a larger number of photo- 

 graphs of sections. 



In the living o.^^ there appear to be at least four constit- 

 uents of the cytoplasm. 



1. The above-mentioned clear, approximately transparent 

 sap globules of varying sizes (Photos, i, 2, 4, 5). 



2. Dense, opaque, deutoplasmic granules, varying in size 

 from tiny points, scarcely visible under a magnification of one 

 thousand diameters, to those plainly seen with the low powers. 

 In form, size, and distribution they appear to answer to the 

 above-mentioned osmophile granules (page 130) (Photos. 4, 

 5, 7-9, 12, 13, and Text-fig. I). These granules dance about 

 with great activity in eggs that have been kept too long in 

 artificial media — this abnormal activity being probably due 

 to pathological disturbances in the rest of the cytoplasm. 



3. Nucleolar-like bodies, strongly refractive in the living Qg% 

 — that do not blacken with osmic. In the sections they react 

 to the stains selected by the nucleoli of the pronuclei. The 

 sperm-granules (4 and 6) react to the same stains. 



4. Lighter areas which are relatively free from the sap glob- 

 ules and osmophile granules — these areas being represented 

 by the polar rings, spindle, attraction sphere, and the inter- 

 spac-es of the sap globules. This substance does not blacken 

 with osmic and appears distinctly granular in fixed eggs. It 

 stains intensely, and in the sections appears more opaque than 

 the rest of the cytoplasm — even in those cases where the 

 osmophile granules are not dissolved or faded out. Thus the 

 lighter areas of the living egg are the darker areas of the sec- 

 tions. {Cf. Text-fig. Ill and Photo. 17.) A study of the living 

 Q.g'g suggests no fundamental difference between that part of 

 those lighter areas which contributes to forming the polar 

 rings, spindle, and sphere (archoplasm (5)), and the part occu- 

 pying the interspaces of the globules. We have been able to 

 demonstrate a difference by differential staining of the sections 

 (5), thus far succeeding only with the double stains. We have, 

 however, additional data on this point arguing strongly for the 

 specific nature of archoplasm. 



Chromosomes in the Living Egg. — The rarity of the cases in 



