58 



Scientific Proceedings (103). 



I have been experimenting with a variety of methods while 

 studying the formation of the insect sperm, more particularly of 

 Hemiptera belonging to the Family Cimicidae (Pentatomidae) • 

 Two new methods were found which have yielded interesting 

 results. 



The first is a modification of the Kopsch method for Golgi 

 bodies, which depends on the reduction of osmic acid by the 

 Golgi apparatus more quickly than by other cell constituents. 

 This modification is more rapid than Kopsch and often gives 

 good fixation of the cell as a whole. The procedure is as follows: 



Fix in glass-stoppered bottles for 20 to 30 hours in Mann's 

 sublimate-osmic : — 



I per cent osmic acid solution I part 



Corrosive sublimate, saturated solution in normal salt i part 



Wash in water over night, dehydrate and embed. Cut sections 

 four micra thick. Mount directly or counterstain as desired; 

 I find light green very useful. Golgi elements are intense black, 

 mitochondria unstained or light brown. This method, in com- 

 mon with all Golgi technique, is more or less uncertain, due not 

 so much to imperfect impregnation as to variability in general 

 fixation. Since working with this method I have found that 

 Weigl has made use of another sublimate modification for the 

 Golgi apparatus. 



The second method bears upon the structure of mitochondria, 

 which, from a chemical standpoint, have been considered as a 

 combination of some lipoid with an albumen. Further, it has 

 been noticed, especially in Lepidoptera and Mollusca, that the 

 mitochondria, occurring as spherical bodies, consist of an outer, 

 intensely staining layer and an unstained medullary substance. 

 Whether any correlation exists between these two facts is un- 

 known. I have found that with Cajal's Golgi apparatus method 1 

 it is possible in the spermatid Nebenkern of these Hemiptera to 

 demonstrate conclusively a compound structure, especially in 

 those stages where the Nebenkern halves are elongating to form 

 sheaths for the tail filament. Here the medullary substance 

 impregnates intensely, while the chromophilic envelope remains 



1 For a readily accessible statement of this method see A. M. Pappenheimer, 

 "The Golgi Apparatus," Anat. Record, 1916, Vol. n. No. 4. 



