PATHOLOGICAL AM1TOSIS IN FOOD-OVA OF FASCIOLARIA. 



transition stages between the unfragmented and the fragmented 

 nuclei for not only are these intermediate stages very rare, but 

 they are unconvincing when found, and the appearance which the 

 fragmented vesicles generally present suggests that the divisions 

 took place quickly, perhaps by explosion. I have, however, in a 

 few cases seen constrictions in several of the fragments as though 

 these were undergoing one or more fissions (Fig. 3). 



Besides showing several cases of what may be fission, Fig. 3 

 illustrates two other degenerative changes which occur when the 

 ova are about to disintegrate. Frequently large vacuoles are 

 found inside of the " nu- 

 cleoli," in some instances 

 apparently bursting out- 

 ward into the nucleoplasm, 

 somewhat as the vacuoles 

 in the external kidneys do 

 ('05). These vacuoles in 

 the "nucleoli" seem to 

 originate from the bubbles 

 of the chromatic froth but 

 of this I am not certain. 

 The other degenerative 

 change is the presence in 

 a few instances of small 

 densely staining masses to 

 which Osborn ('04) has 

 drawn attention, and which 

 he compared to the " spore- 

 like bodies" described by 

 Herrick ('92) in the degen- 

 erating nuclei of the yolk 

 cells in the egg-nauplius of Alpheus. These bodies I believe are 

 condensations of the chromatin, and they may be found lying 

 either in the "nucleolus," or outside it in the nucleoplasm. 



In concluding his section on the nuclear phemomena in the 

 food ova, Professor Osborn says: "The cells in which the nuclei 

 have undergone these changes are on the road to complete break- 

 down, and these changes are the last events in their lives. The 

 process is a futile attempt at segmentation where normally we'. 



Fig. 3. Fragments of two germinal vesicles 

 showing "spore-like bodies" in upper right 

 hand fragment; vacuoles in the "nucleoli"; 

 and what may be cases of fission. The large 

 black bodies represent yolk. 



