GERM CELLS OF GRYLLOTALPA 309 



plasm during the growth period. I have not studied the fertili- 

 zation stages and hence cannot say whether mitochondria are 

 carried into the egg by the spermatozoon. What few observa- 

 tions I have made, then, are not conclusive as to the origin or 

 the genetic continuity of these structures. They indicate, how- 

 ever, that they are genetically continuous. At any rate, in the 

 male, they do not arise in the growth period, but are continuous 

 from the spermatogonial stage, through the growth period, the 

 maturation divisions and the transformation of the spermatid. 

 In the female they are present in the oogonia and continuous 

 during the early growth period or as far as I have followed them. 

 While I am willing to admit that the mitochondria may be con- 

 tinuous structures, I am not inclined to ascribe to thsm any 

 value in heredity, at least in the present state of our knowledge. 



3. THE ACROSOME 



Late telophases of the second spermatocyte division show the 

 reconstructed nucleus and the mitochondrial mass lying near it 

 (plate 2, B) . In this figure most of the spindle still remains, but 

 it has partly disappeared at one end, where there is no indica- 

 tion of the remains of the aster to form an idiozome or Neben- 

 korper. In fact, in later stages, the spindle and asters disappear 

 completely. Plate 2, C, shows there is nothing in the cytoplasm 

 of the young spermatid except the mitochondria. I emphasize 

 this fact, as the acrosome has been described as arising from the 

 Nebenkern. The next stage following that shown in plate 2, 

 C, is shown in plate 2, D and E. It will be noted that there are 

 two additional bodies present at this time ; one elongated, curved, 

 and in contact with the nuclear wall, the other a small spherical 

 body. Both stain very intensely with iron haematoxylin. Many 

 cysts showing thousands of cells in this stage have been found. 

 I have no knowledge of the origin of these bodies, although a 

 large amount of material has been carefully examined. It would 

 seem that they arise de novo in the cytoplasm as they are not 

 present in the young spermatid. The spherical body cannot be 

 the chromatoid body, as this structure is present in all the 

 spermatids at this stage of transformation. Later it passes into 



