BARBER: HEREDITY IN CERTAIN MICRO-ORGANISMS. 13 



were none at all in the new race cultivated under similar 

 conditions. 



Many spores of both race and check were separated from the 

 vegetative cells and isolated in fresh nutrient fluid. In some 

 cases the mother-cell containing ripe spores was isolated, while 

 in others spores were removed from the mother-cells and iso- 

 lated in separate droplets. The earlier stages of the germina- 

 tion of the spores were usually observed, so as to make sure 

 that the new growth was of spore origin. During a period 

 of nearly two years about fifty such isolations of spores or 

 spore groups were made, of which about one-third were taken 

 from cultures of the new races. Since, in a considerable 

 number of cases, mother -cells with four spores or larger 

 spore groups were included in one isolation, the total number 

 of spores under observation was perhaps 200. A very small 

 proportion of these spores developed further than the forma- 

 tion of a few buds or of a small colony. In some cases a col- 

 ony of several hundj'ed cells would be formed, but no further 

 development could be obtained. From spores or spore groups 

 isolated from the check not above five permanent cultures 

 were obtained, and from the new races none. It is probable 

 that the culture used had, through long cultivation, partially 

 lost its power of producing healthy spores. 



Cultures obtained from spores of the check, whether feeble 

 or permanent, showed a great irregularity in the form and 

 size of cells. These cells closely resemble those from the 

 new races originating in varying vegetative cells, exhibiting 

 much the same elongated form and tendency to group. Be- 

 sides microscopical differences, these new spore races show 

 macroscopical abnormalities in liquid media. Growth is less 

 vigorous, scanty or no pellicles are formed, and there is a 

 greater tendency for the growth to collect in the bottom of 

 the test-tube, leaving a clear liquid above. A culture originat- 

 ing from spores of the check showed both macroscopical and 

 microscopical abnormalities unimpaired after over two years 

 cultivation on various media. 



As stated above, no permanent culture was obtained from 

 spores of the new race, though in one case a colony of about 

 500 cells was obtained, and in another one of 100 or more. 



