376 R. W. GLASER AND J. W. CHAPMAN. 



BIO-CHEMICAL OBSERVATIONS ON THE POLYHEDRAL BODIES. 



According to Tubeuf, Krassilschtschik, Prowazek, Wahl, Wolff, 

 Glaser and Chapman the polyhedral bodies are regarded as 

 being reaction products; towards bacteria (Tubeuf, Krassilsch- 

 tschik) or towards Chlamydozoa (Prowazek, Wolff) or towards 

 an unknown virus (Wahl) or towards a filterable virus (Glaser 

 and Chapman). According to Bolle, Fischer, Marzocchi, and 

 Knoche the polyhedral bodies are stages of a protozoan ; accord- 

 ing to Escherich and Miyajima they are bearers of an unknown 

 virus. 



It seems that the views are very diverse as regards the true 

 nature of the polyhedra. For this reason it was thought advis- 

 able to submit some of our bio-chemical work on this subject in 

 further support of our contention, obtained from morphological 

 and experimental studies, that the polyhedra are merely organic 

 degeneration-products of the disease. 



During the gipsy moth season great quantities of diseased 

 material can be obtained. For this reason all of the bio-chemical 

 investigations were performed with gipsy moth polyhedra. These 

 bodies are heavier than water and consequently can be obtained 

 in bulk by centrifuging aqueous emulsions of diseased material. 

 By repeated washing, filtering and centrifuging most of the fat, 

 cellular debris, etc., can be eliminated. After this treatment 

 the polyhedra were always washed with ether in order to free 

 them from any possible remnants of adhering fat. Thorough 

 attention to this cleansing operation will yield polyhedra in a 

 fairly pure state for chemical tests. The material was allowed 

 to dry naturally in the centrifuge tube, after which the lump 

 that formed at the bottom could be loosened and transferred to 

 a mortar where it was pulverized. This pulverization if done 

 gently does not crack or injure the polyhedra in any way. After 

 this procedure the mass of polyhedra look very much like pul- 

 verized chalk. It is comparatively easy to obtain 2 or 3 grams 

 of polyhedra from about one or two hundred caterpillar cadavers. 



As the polyhedra do not blacken with osmic acid, and do not 

 stain with Sudan III., it seems unlikely that they contain fat. 

 They stain with picric acid, however, and this gave us the clue 

 to their possible protein nature. The color tests for dry proteins 



