I20 FATE OF ORGANISMS EATEN BY LARVA 



"Cultures from 37 flies which emerged from Morgan infected larva; gave numerous 

 colonies of non-lactose fermenting bacilli. Three out of the many isolated proved to 

 be examples of Morgan's bacillus. Cultures were made on agar from 95 of the flies 

 which emerged from larvie infected with the spores of B. anthracis. 



"Cultures from ir out of 14 newly hatched flies showed B. anthracis (78 "/u). 



" Cultures from 48 out of 62 flies one day old showed B. anth)-acis (78%). 



" Cultures from -2 out of 8 flies 3 days old showed B. anthracis ii^.'^l^). 

 ,, I „ 6 ., 4 ,. ,. ,. (i67o). 



„ I „ 5 „ 6 „ „ „ (20%). 



"Positive results were olitained from 63 (66 "/o) out of the 95 flies examined. A 

 few of the flies which emerged were kept in a clean cage without food and died in a 

 itSY days. After they had been dead some weeks cultures were made from three of 

 them. B. anthracis was found in cultures from two." 



These experiments appear to indicate that non-spore pro- 

 ducing organisms such as B. prodigiostis, B. enteritidis and 

 certain cocci, which are not adapted to the conditions prevaihng 

 in the interior of the larva and pupa, seldom survive long enough 

 to appear in the adult. Morgan's bacillus, however, which is 

 sometimes found in the intestine of the fly under natural 

 conditions, appears to be capable of surviving. Colonies of 

 various non-lactose fermenting organisms were frequently found, 

 a fact which seems to show that many organisms of this class 

 are specially adapted to the conditions which prevail in the 

 intestine of the larva and of the adult fly. Many cocci and 

 other organisms are also capable of surviving during the meta- 

 morphosis. 



The spores of B. anthracis persist, and are present in a large 

 proportion of the adults which develop. The spores of other 

 bacilli can probably behave in the same way. 



Series III. 



The third series of experiments was undertaken in order to 

 compare the results obtained by breeding larvit in different 

 artificially infected foods. 



" Sets of card cream boxes containing sterile sand were prepared. In one set was 

 placed food consisting of cooked meat and potato sterilized in the autoclave, in the 

 second human fiT;ces sterilized in the autoclave, and in the third unsterilized human 

 faeces. In the first and second sets the organisms originally present had been 

 destroyed. One box of each set was infected with B. typhosus, one with B. enteritidis, 

 one with Morgan's bacillus, one with />. prodigiosus, and one was kept as a control. 

 Flies were placed in a cage containing sterile food and the eggs and young larv;e 



