184 ANTHRAX 



Experiments on Larv(2. 



Graham-Smith (191 1, p. 43) allowed the larvae of blow-flies 

 {C. erythroccpJiala) to feed on meat artificially infected with the 

 spores of B. anthracis. 



"Altogether about 70 flies emerged. Of these 17 Mere dissected and cultures 

 made from these organs a few hours after emerging. From four specimens B. 

 anthracis was not cultivated, but from the other 13 cultures were obtained. It was 

 present in the intestinal contents of 10 ; on one or both wings of 8 ; on one or more 

 legs of 12, and on the heads of 8. 



"Three specimens were dissected after living two days in a cage. From the legs, 

 wings, crop and intestinal contents of all B. anthracis was obtained. One specimen 

 three days old was dissected, and B. atithracis was obtained from one wing. 

 B. anthracis was cultivated from a leg and from the head of a specimen 6 days old." 

 Three specimens were dissected after living 10 days in a cage. B. anthracis was 

 obtained in culture from two of them. Six specimens 11 days old were dissected, and 

 B. anthracis obtained from three. Three flies 15 days old were dissected and 

 B. anthracis cultivated from two of them. B. anthracis was cultivated from one leg 

 of one of three flies 19 days old, which were dissected. Several of these cultures, in- 

 cluding that obtained from a fly 15 days old, were proved to Ije fully virulent. 



Two flies 22 days old, three 23 days old, two 29 days old, three 30 days old and two 

 33 days old were dissected, and cultures made from their limbs and organs, but 

 B. anthracis was not found. 



"A few other experiments were carried out with these flies. Four flies were 

 allowed to walk over agar plates a few hours after emerging. Numerous colonies of 

 B. anthracis developed on these plates. 



"Twelve flies a few hours old were kept in a glass cage, and fed on syrup. Shortl)' 

 after their first meal some of the remains of the syrup on which they had been feeding 

 was smeared on the surface of agar plates. Numerous colonies of B. anthracis 

 developed on these plates. Nearly every fly very shortly after emerging deposited a 

 large quantity of whitish, semi-fluid material. Cultures made from this material were 

 negative. The fa;ces deposited by flies two days old contained B. anthracis in 

 considerable numbers, as also did the remains of syrup on which they had fed. 



" i^. anthracis was not found in cultures made from the faeces of flies 22 and 23 days 

 old, nor in those made from the remains of syrup on which they had been feeding, 

 but a single colony of B. anthracis was obtained from the remains of syrup on which 

 flies 21 days old had fed." 



Not infrequently anthrax-like colonies occur on plate cidtures made from flies, 

 but these can usually be distinguished in subcultures from B. anthracis without any 

 difficulty. 



Another series of experiments (Graham-Smith, 191 2, p. 333) 

 was conducted with the larvae of house-flies {AT. doviesticd) fed on 

 material infected with anthrax spores. 



