THE MITOCHONDRIA AND OTHER STRUCTURES. 1 13 



as normally but the axial filament grows out within the cell, the 

 mitochondria develop as normally in connection with the axial 

 filament and form the same long threads, although in this case 

 these threads are wound round and round within the cell (Figs. 

 47 and 48). 



The origin of the mitochondria is still unsolved. They cer- 

 tainly do not arise in the male germ cells, since they are already 

 present in the earliest germ cell. There is no evidence in the 

 above observations that the mitochondria are formed at the 

 expense of any nuclear material. Also there is no evidence that 

 the mitochondria of the male germ cell of Chorthippus curtipennis 

 can have any influence upon inheritance, as was suggested by 

 Meves ('13) in his work on Ascaris, unless it can be shown that 

 the tail as well as the nucleus of the spermatozoon enters the egg. 



CONCLUSION. 



The mitochondria as well as the neutral red granules are present 

 in the primary spermatogonium of Chorthippus curtipennis and, 

 while the neutral red granules appear to have no definite behavior, 

 the mitochondria do behave in a characteristic manner through- 

 out the development of the male germ cells. By means of the 

 tissue culture method the mitochondria can be seen to be present 

 as small, delicate granules in the primary spermatogonium. They 

 increase in amount during the growth stage and arrange them- 

 selves along the spindle in a definite manner during the spermato- 

 cyte division. They form the nebenkern of the spermatid and 

 from this develop into two equal homogeneous threads in the tail 

 of the spermatozoon. 



WOODS HOLE, MASS., 

 September, 1915. 



LITERATURE LIST. 

 Chambers, R. 



'15 Microdissection Studies on the Germ Cell. Science, N. S., Vol. XLL, 



No. 1051. 

 Coghill, G. E. 



'15 Intracellular Digestion and Assimilation in Amphibian Embryos. Science, 



N. S., Vol. XLII., No. 1080. 

 Davis, H. S. 



'08 Spermatogenesis in Acridida? and Locustida?. Bull. Mus. Comp. Zool. 

 Harvard College, Vol. LIII, No. 2, p. 59. 



