56 ROBERT SCHARPF. 



specially well seen in fig. 9, n. /., representing a nucleus and its 

 surrounding protoplasm of a middle-sized gurnard's egg. 



I agree with my friend Dr. Will in not attaching any morpho- 

 logical significance to the nucleoli. They must be regarded as 

 large masses of chromatic substance. In some instances they 

 are entirely absent • in others one or more may be present. 



To return to the large nucleoli which, as has been men- 

 tioned, are occasionally present in the ova of the gurnard, they 

 are never wanting in the eggs of the conger eel (Conger 

 vulgaris). They stain slightly darker than the small ones. 

 In several cases (fig. 5, n') I noticed a small nucleolus being 

 constricted off from a large one. In an egg of Gadus virens 

 (fig. 6), measuring 0*105 mm. in diameter, the dark protoplasm 

 {vr. 1 ) surrounding the nucleus in smaller ova had been sepa- 

 rated in form of a ring, and internally to it another narrower 

 ring (p/*. 2 ) of protoplasm was frequently present. The zone 

 of light protoplasm externally had increased considerably 

 meanwhile. In some instances, however, the dark zone had 

 invested the whole of the ovum, and the light portion had 

 entirely disappeared. Another feature which came under my 

 notice now was that the dark zone contained the faint outlines 

 of spots corresponding in size to nucleoli (fig. 7, sp.), none of 

 which, however, were seen outside in the light protoplasm. 

 Only in Hippoglossoides did I occasionally observe similar 

 spots close to the surface of the egg. 



There can be little doubt that these spots are nucleoli which 

 have travelled through the nuclear membrane into the sur- 

 rounding protoplasm, and are gradually dissolved there. I 

 notice here incidentally that possibly some find their way to 

 the surface of the egg to form the nuclei of the follicular epi- 

 thelium. This is only a supposition • but it will be referred to 

 again more fully in a subsequent chapter. 



In a larger egg of Gadus virens, 0'132 mm. in diameter 

 (fig. 7), we still find a granular protoplasmic ring round the 

 nucleus ; however, a great change has come over the nucleoli, 

 which are now no more closely attached to the nuclear wall. 

 They seem to have become broken up or dissolved in some 



