4 HAROLD H. PLOUGH. 



new granules of this sort are being gradually formed. While 

 these granules cannot be followed during the spermatogonial 

 divisions there seems little doubt that they lie inert in the cell 

 and their distribution is merely hit or miss to one or the other 

 of the daughter cells. 



After the last spermatogonial telophase the nuclei enter on the 

 stage shown in Fig. 2, in which the chromatin appears as a light 

 network in prepared material. This network shortly becomes 

 aggregated into flocculent masses corresponding roughly in num- 

 ber to the diploid number of the chromosomes. This "massive 

 body" stage is beginning to appear in Fig. 3 and Fig. 4. The 

 mitochondria in these early stages of the growth period are 

 extremely difficult to demonstrate in fixed material as indeed 

 they are throughout the spermatogenesis even by the special 

 technique for mitochondria. At times, however, a cloudy mass 

 can be seen forming a cap over one side of the nucleus (Fig. 2). 

 With janus green, however, they become very prominent in the 

 Jiving material. The granules are larger and seemingly in greater 







numbers than in the spermatogonia. The details of their be- 

 havior are similar to those in Chorthippus, except that here again 

 there is no tendency to assume the thread-like form. 



Throughout these earlier stages of the growth period a mito- 

 .some, the remains of the last spermatogonial division, is present. 

 Often an actual bridge between the two daughter cells persists 

 for a short time after the division is complete. This is the condi- 

 tion seen in Fig. 3. The mitosome rapidly disappears after the 

 stage shown in Fig. 3, and is never found after the "massive 

 body" stage. At about this time there appears in about the 

 center of the cytoplasmic mass a more or less definite sphere 

 which is browned by osmic and only slightly stained by hsema- 

 toxylin. At first I took this to be a mitosome, which it strongly 

 resembles, but later it was found that a definite mitosome was 

 present at the same time, as shown in Fig. 3. The sphere is 

 shown with great clearness in Fig. 4, where it lies in a large 

 vacuole probably due to imperfect fixation which is sur- 

 rounded by masses of mitochondria. This sphere is not visible 

 in the living cells, whether stained or not, but its presence can 

 be inferred from the fact that in the growth period the mito- 



