16 KANSAS UNIVERSITY SCIENCE BULLETIN. 



instances were found among the offspring of single normal 

 cells isolated on the previous day. 



A large number of these cells failed to grow when isolated, 

 and checks consisting of single normal cells isolated and 

 brought to a successful growth under parallel conditions are 

 evidence that the failure to grow is referable to the nature of the 

 abnormal cells and not to the condition of growth. During 

 a period of about two and a half years no less than fifty cells 

 of the typical sport type, or otherwise abnormally elongated, 

 were isolated. From these isolations less than ten new races 

 of permanent character were obtained. 



The early development of the new races is slow, and, as 

 stated above, they often exhibit during the first few days a 

 connected mass resembling a mycelium of the higher fungi. 

 But after budding has once freely begun the new races are 

 as vigorous as the type. 



About two years after its origin, a new race of Saccliaro- 

 myces anomahi.s was tested as to its powers of competition 

 with the parent type when mixed with it in cultures. A 

 single cell was isolated from the parent type, and one from 

 the new race, and, after growth had well begun in hanging 

 drops, an approximately equal number of offspring of each 

 cell were mixed and transfers made from the mixture to one 

 per cent, glucose broth in test-tubes, to one per cent, glucose 

 agar, and to hanging drops of glucose broth. After two days' 

 growth transfers were made from each of the three cultures 

 to fresh media of the same kind. These transfers were re- 

 peated every two or three days through eight subcultures, 

 the experiment lasting twenty-three days. At the end of 

 this time it was found that the new race had persisted in the 

 hanging drop cultures, had apparently outgrown the parent 

 type in both pellicle and sediment of the broth test-tube cul- 

 tures, but had so far diminished in the agar cultures that at 

 the margin of the growth it had nearly disappeared and was 

 but little more evident at the center. The hanging drop cul- 

 ture was kept at room temperature ; the test-tube cultures 

 at about thirty degrees C. 



The agar series was further continued to the fifteenth sub- 

 culture, and during the last seven transfers it was kept at 



