RELATIONSHIP BKTWKKN A RED TORULA AND A MOLD. l6l 



2. The number of etherizations incident to these experiments 

 never exceeded two in number nor more than 7 minutes in 

 duration (8). 



3. The conditions, under which the flies were reared and 

 experimented upon, were practically ideal as to number in jars, 

 ventilation, etc. (9, 10, u). 



SUMMARY AND CONCLUSIONS. 



1. A red torula has been found as a contaminant of certain 

 commercial yeast and a brief biological description given. 



2. The combined growth of this torula and one of the group of 

 Penicillium produces a bright lemon-yellow color. 



3. Overgrowth of the torula by the mold transforms the 

 creamy torula colony into a hard, tough mass, apparently by 

 invading the colony and matting the cells together. The torula 

 cells suffer by the contact. 



4. The pigment of the torula has the properties of an acid- 

 alkali indicator. Its sensitivity to these reagents is low. 



5. The red torula may be used for raising batches of D. 

 melanogaster. 



6. A mold, probably closely related to Penicillium glaucum 

 has been shown to have the power of killing D. melanogaster. 

 The mechanism by which it injures the flies is shown to be 

 possibly of two sorts. First, it appears to grow among the torula 

 cells in the gut of the fly and by matting them together forms a 

 more or less solid mass which may block both elimination and 

 engorgement. By invasion of the intestinal wall, the mold hyphje 

 are believed to bind this mass firmly in the intestine. Second, 

 it is believed that the mold actually invades the tissues of the fly. 



BIBLIOGRAPHY. 



1. Robaud, E., and Descazeau, J. 



'23 "Sur une agent bacterien pathogene pour les mouches communes. 

 Bad. delendcE-muscce, n. sp." Compt. Rend. Acad. Science, Paris. 

 177: 716. 



2. Glaser, R. W. 



'24 "A Bacterial Disease of Adult House Flies." Am. Jour. Hyg., 4: 411, 



3. Fresenius. 



'50 " Beitrage zur Morphologic," Frankfort, 63. 



