Germ Cells of Leptinotarsa Signaticollis. 143 



really nutritive in function? The evidence for believing so rests 

 on their close relationship to the germ cells, and on the changes 

 undergone in size and form after coming into contact with the 

 germ cells. It seems to be the general concensus of opinion that 

 these cells later form the follicle of the egg by surrounding the 

 latter as it passes from the lower region of the terminal chamber; 

 but I believe it can be readily shown that the follicle is not formed 

 in this manner. The evidence for this will be given in its place a 

 little later. 



Closer examination of the germ cells in the stage shown in Fig. 

 1, reveals the presence of one or two basic-staining nucleoli, each 

 surrounded by a clear non-staining area (Fig. 34) . This condition 

 proves to be the result of the division of a single nucleolus, and 

 this is the first step in what appears to be a process of amitosis. 

 The division later extends to the nucleus as shown in Fig. 35. A 

 fuller discussion of this process and its significance will be con- 

 sidered in connection with the germ cells of the male. 



In Fig. 2, which is from a very young pupa, we find a considerable 

 increase in the number of cells in the ovariole, brought about by 

 mitotic divisions which are very abundant at this and succeeding 

 stages, especially among the germ cells. Mitotic figures among 

 the epithelial cells are very rare, but as they do occur, it is 

 inferred that mitosis is the method of cell multiplication, for I 

 have never observed authentic cases of amitosis among these cells 

 at this stage. The region of the terminal thread is much larger in 

 diameter than in Fig. 1. The cells at the base of the thread show 

 a tendency to flatten out, and the lower margin of these flattened 

 cells represents the position of the future limiting membrane 

 which will definitely separate the terminal chamber from the 

 terminal thread. 



Fig. 3 is from a slightly older pupa, and shows at l.m. more 

 distinctly the place where the limiting membrane will form. Just 

 below this is seen a double row of epithelial cells, which compared 

 with those surrounding the germ cells lower down, show consid- 

 erable differences in form and size. The latter are smaller, and 

 the nuclei are bean-shaped. These transformations suggest that 

 these cells are in some way concerned with the metabolism of 



