proceedings: biological society 315 



Some natural groups in aspergillus: Charles Tiiom. (Illustrated 

 with cultures.) A large number of strains obtained in cultures of 

 Aspergillus fall into a series of natural groups. In these groups certain 

 general morphological and physiological characters prevail. The 

 differences between the members of the groups are for the most part 

 quantitative rather than qualitative. In the Aspergillus niger group, 

 the amount or intensity of color varies markedly among the individuals, 

 other characters remaining the same. Individuals with exactly the 

 same color and morphology, show markedly different physiological 

 activities. The differences between these latter physiological forms 

 is certainly as important as the mere difference in the amount of color 

 secreted in the spore, which difference has been commonly accepted 

 as a basis for specific description. 



Another great group may be made of the forms giving the mor- 

 phology of Aspergillus flavus. In this series again the same condition 

 exists as noted in the Aspergillus niger group. Aspergillus fumigatus 

 and A. nidulans form two closely related series of organisms. 



Several similar series may be made but the point clearly brought 

 out is that there is evidence of mutation among these forms in 

 which a single morphological or physiological character appears to 

 separate one strain from the typical strain of the series as at present 

 described. Within each group differences are easily recognizable, 

 some of which are determinable only by chemical or physiological 

 means. The solution of the taxonomic difficulty offered is that each 

 group shall be designated by the name of one of its well-known species 

 excepting when particular strains have become important economically 

 or physiologically, and must therefore receive some further form of 

 identification and description. 



H. L. Shantz, Corresponding Secretary. 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 569th regular meeting of the Society was held in the Assembly 

 HAll of the Cosmos Club, Saturday, April 7, 1917; called to order at 

 8 p.m. by President Hay; 45 persons in attendance. 



Under the heading "Brief notes and exhibition of specimens" Dr. 

 R. W. Shufeldt exhibited lantern slides of living California quail, 

 calling attention to their rapidly diminishing numbers. Dr. L. O. 

 Howard called attention to a specimen that had lately come to his 

 notice, the cocoon of a Cecropia moth containing moonstones. He 

 expressed the opinion that they had been placed there by a thieving 

 crow or bluejay. Mr. A. W. Wetmore stated in this connection that 

 he has seen bluejays insert small acorns and kernels of corn into large 

 cocoons. 



The regular program consisted of two communications: 



Alexander Wetmore and Francis Harper: A note on the hiber- 

 nation of the mud-turtle. The authors reported finding a specimen of 

 Kinosternon pennsylvanicum shortly after it had left its underground 



