166 Harry Lewis Wieman. 



area with its green nucleus bears some resemblance to an egg in 

 early stages, led to the suggestion that this might be a part of the 

 regular development of the egg. However, I soon found that 

 most of the eggs do not undergo such transformations, but 

 develop as has been described, from the germ cells at the base of 

 the chamber. 



Inasmuch as these peculiar configurations are of no significance 

 as manifestations of the general degeneration associated with 

 specialized function of the nurse cells, or in the production of the 

 nutritive stuff for the eggs, or lastly, in the normal process of egg- 

 building; I have reached the conclusion that the process is one of 

 phylogenetic significance, in which certain of the nurse cells are 

 passing through alternating conditions of oxidation and reduc- 



FiG. Y. Semi-diagrammatic drawing of the testis, one of the lobes being turned 

 through an angle of ninety degrees, c, cap-like region opposite the sperm duct; 

 /, follicle; sp. d., common sperm duct of one side. 



tion similar to those undergone by the egg (for it is to be remem- 

 bered that these cells are really germ cells that have lost their 

 reproductive function). There is no evidence that functional 

 eggs result from this process. It can be readily shown that the 

 eggs that are differentiated at the base of the chamber do not exhi- 

 bit these changes. The possibility of two methods of egg forma- 

 tion might be considered, but there is no indication of dimorphism 

 in the offspring, such as would be expected. On the other hand, 

 the possibility of reproductive cells from either source producing 

 identical offspring, meets the objection that there are more than 

 enough germ cells differentiated at the base of the egg chamber to 

 account for all of the eggs laid. 



