SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 141, PL. 26 



Bacteroids from Blattclla (jcniiaiiica. A, Part of abdomen showing mycetocytes in fat body, X 225. 

 B, Lobe of fat body showing 3 mycetocytes, X 750. C, Single mycetocyte; bacteroids appear hollow 

 as result of fixation in Carnoy's fluid, X 1725. D, Smear of fat body showing bacteroids in various 

 stages, X 1800. (All preparations and photographs through the courtesy of Dr. Marion A. Brooks.) 



