GROWTH OF EGGS AND EGG-STRINGS IN NEPHELIS. 205 



before they become detached from the ovary-wall, a series 

 of changes begins in some of the germ-cells which ends in 

 the formation of the primordial ova. 



The first step consists in the multiplication of the nucleus 

 with a simultaneous enlargement of the cell-substance. 

 Several cases are seen (in fig. 4) of cells containing two 

 nuclei. Fig. 5 represents a string which is about ready to 

 become free. Here one cell with three nuclei is seen on the 



A glance at fig. 4 will make it plain that the single nuclei 

 vary considerably in size ("006 — "009 mm.) . The size of twin 

 nuclei) fig. (4) also diff'ers much ('007— '013 mm.). The 

 nuclei not only increase in size but also present an aspect 

 quite different from that of most single nuclei. They are less 

 regular in form, clearer, and less strongly stained with car- 

 mine. The nucleolus is either absent or broken into small 

 pieces. The twin or multiple nuclei lie embedded in an 

 area of granular protoplasm, which differs in no particular 

 from the smaller areas containing each one nucleus. While 

 the growth of the germ-cells into multi-nucleated masses is 

 provided for, at least in part, by the breaking down of other 

 cells, I do not think that the pabulum thus provided is taken 

 in massive forms, or that whole cells are swallowed after the 

 manner of an Amoeba. There is always a distinct boundary 

 to the multi-nucleated masses, although no proper membrane. 

 There is abundant evidence of the division of nuclei, but 

 none at all that these clusters of nuclei arise by the coales- 

 cence of as many cells. In fig. 5 there is one much elon- 

 gated mass of protoplasm with three nuclei. It is not 

 impossible that this mass represents two enlarged germ-cells 

 in process of coalescing, but it is more probable that it arose 

 from a single germ-cell. 



The further history of this mulberry stage of the nucleus 

 must be learned from sections of the free egg-string. 



V. The Egg-strings and the Formation of the 

 Primordial Ova. 



Each ovarial tube always contains a number (3 — 5) of free 

 egg-strings (fig. 2), the different parts of which show dif- 

 ferent stages in the formation of ova. 



The egg-string is a club-shaped body, from 2*5 to 4-8 m.m. 

 in length, and from '35 to '50 mm. broad at the widest part. 

 As will be seen from fig. 6, the wider portion is much nearer 

 one extremity than the other, and it is in this portion that 

 the more advanced stages of the ova are found. The larger 



