STUDIES ON INSECT SPERM ATOGENESIS. 8 1 



EXPLANATION OF PLATES. 



All of the figures have been outlined as far as possible with the camera 

 lucida at an initial enlargement of approximately 3,800 diameters. At so great 

 an enlargement it has, of course, been necessary to correct the outlines ex- 

 tensively and to add much of the finer detail free hand. In reproducing, the 

 figures have been reduced uniformly to an enlargement of approximately 3,000 

 diameters. In every case the method employed in the preparation of the 

 original object has been indicated. 



