﻿1903] OOGENESIS IN SAPROLEGNIA 239 



the chromatin returns to the granular condition generally pres- 



ent in resting nuclei. 



Following mitosis, the oogonium passes into a condition that 

 IS exceedingly difficult to study. The number of nuclei has 

 been doubled by the division, but the daughter nuclei are much 

 smaller than the parents. A comparison oi fig, 4 with 7%-. 10 

 will illustrate well the change. It is not the small size, however, 

 that makes the examination so difficult, but the fact that these 

 nuclei very shortly show signs of degeneration. Almost all of 

 the nuclei are affected. The nuclear membrane becomes indis- 

 tinct, and its contents finally lie as granular matter in a clear 

 area that resembles, and probably is, a vacuole. The granular 

 matter is undoubtedly derived In large part from the nucleolus 

 that fragments, but some of It maybe chromatin. The study of 

 the steps in this process of general degeneration is especially 

 baffling because the progress is toward a time when the nuclear 

 material becomes indistinguishable from other granules in the 

 cytoplasm. 



It is difficult to understand how Humphrey and Hartog could 

 ever have Interpreted this process of degeneration as successive 

 nuclear fusions. As Trow pointed out, successive fusions should 

 give more and more conspicuous nuclei, as the material accumu- 

 lated with each union, and consequently an ever-increasing 

 clearness of conditions. In reality, however, we pass from the 



A 



o 



's. II, 14, and 75. The last two figures 

 der than those shown in figs. lo and //, 

 and illustrate late stages in the process, when the nuclear mem- 

 branes have mostly disappeared and the nucleoli and possibly 

 chromatic material lie in vacuoles. Such vacuoles are frequently 

 elongated, and when they contain two masses of deeply staining 

 material there is suggested a stage in nuclear fusion, and such 

 appearances probably deceived Humphrey and Hartog. How- 

 ever, the vagueness of structure and manifest waning of the pre- 

 vious clear definition should have put these observers on their 

 guard. These degenerate nuclei remain for a long time, even 

 after the eggs are fully formed, and it is quite impossible to tell 

 with exactness when they lose their structure and functions. 



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