No. 2.] THE OVARIAN EGG OF LIMULUS. l8l 



chromatin granules from the germinal vesicle cannot explain 

 the extension of the inner granular zone towards the point of 

 attachment of the egg, as it can be seen both in sections and 

 in the living egg of Limulus (PL XIII, Fig. i6). 3. Contrary 

 to the results of Calkins, the internal granular zone does not 

 behave like ordinary nuclear chromatin towards the Biondi- 

 Ehrlich triple stain. In the degenerating eggs described in 

 another chapter, the chromatin that is found in considerable 

 quantities in the cytoplasm, and having the form of nuclei, 

 does take the green stain with the Biondi-Ehrlich mixture 

 (PI. XIV, Figs. 30, 31). 



I can find no reason, therefore, for concluding that the deeply 

 staining granules of the inner zone are eliminated chromatin 

 granules. 



On the other hand, it has been shown that the epithelial 

 cells of the ovarian tube and of the egg stalk secrete a sub- 

 stance which, under the influence of reagents, becomes granu- 

 lar, and that this substance is seen at times to accumulate at 

 the point of attachment of the egg (PL XIV, Fig. 22, y.s). 

 From a consideration of the foregoing objections and the facts 

 presented by such appearances as are represented in PL XIII, 

 Fig. 16, and PL XIV, Figs. 19, 20, 22, as well as from the fig- 

 ures of Korschelt ('89) in the case of insect eggs, I conclude 

 that this secretion enters the egg and is carried along toward 

 the germinal vesicle, where, acted upon by the hyaline karyo- 

 lymph derived from the " Nebennucleoli," it becomes con- 

 verted into a stainable substance which I will call nietaplasrn. 



While I have called the extension of the inner zone towards 

 the stalk of the egg a channel, I do not mean to imply 

 by that term that it is a tube in the sense in which Balbiani 

 ('83) used the term in the case of the egg of Geophilus. It 

 appears to be rather the expression of the existence of an 

 interfilar fluid or substance, which, for the time being, does 

 ■ not mix with the surrounding hyaline cytoplasmic matrix, and 

 which is especially favorable for the entrance and chemical 

 modification of the crude food material which serves the egg 

 as nourishment. I would not therefore regard the inner 

 hyaline zone as an open space in the sense of Leydig, nor as 



