Feeding Insects with Bacilli. By Br. R. L. Maddox. 6U7 



diameter of the human blood- corpuscle. Seen on one surface they 

 appeared circular and bright, with a central dot ; seen on the 

 reverse side, the largest had a pale centre, then a darkish ring, 

 then a pale ring surrounded by a dark outline. The window-frame 

 could be, with a httle care, focused on this surftice, but not on the 

 opposite side. Seen in side view they were concavo-convex, the 

 protoplasm forming a dark body like a comma lying closely against 

 the inner edge of the outer convexity. Most of them had a 

 gentle rolling, tumbling kind of motion, often springing up sud- 

 denly and being for the moment lost to view, but directly after 

 found in ths same spot. This springing occurred only when seen 

 with the ringed side upwards. It seemed as if the little organism 

 had got twisted upon flagella which suddenly untwisted, throwing 

 the object immediately out of focus, though I could not with cer- 

 tainty detect any flagella. The organism was quite new to me. 

 In the other three dejections nothing of moment was noticed, save 

 a very lew of the same organisms and a few rods in the solid por- 

 tion, the longest being beaded. The wasp was exceedingly restless 

 all the forenoon. The blow-fly some little time after feeding on 

 the sugar with the blood-mixture had a dejection, which was 

 directly examined, and found to contain a few beaded rods amongst 

 a considerable amount of debris. The rods in each resembled the 

 anthrax rods. 



267/i a7id 27th. — Again fed on the sugar moistened with dis- 

 tilled water, and a humble bee (Bomhus lajpidarius) which had 

 been captured on the 27th, was fed in the same way. A dejection 

 from it that had been passed on to the square of glass was ex- 

 amined and furnished amongst the debris a few very thick short 

 non-motile rods with rather pointed ends. 



On the 28th, after changing the vessels and feeding with sugar, 

 the three insects were unfortunately placed on the outside window- 

 ledge in fall sunshine, the window being slightly open. All were 

 found dead at 3 p.m., supposed to be due to the powerful heat of the 

 sun and a very free current of air. In the perivisceral cavities of 

 the wasp and Bomhus nothing of moment was noticed. The fly 

 was not examined. The beetle {Blivps mortisaga) had not been 

 fed on the blood-mixture, but on a variety of ordinary food-articles, 

 and is still living. 



That specimen of anthrax blood, it seems, was not pathogenic 

 to the fly or wasp. The death of the three insects appeared to be 

 solely due to the high temperature (136" F.) under confinement 

 (heat asphyxia ?), as all were lively enough when the vessels wcro 

 changed. 



