Jan. 15. 1930 Further Studies of Soros porella uvella 401 



merely a name applied to species of Entomophthora in which only rest- 

 ing spores are as yet known. 



Although Krassilstschik's description of Tarichium uvella is meager 

 and unaccompanied by figures, the measurements and characteristics of 

 the singular resting spores which are peculiar to this parasite are clearly 

 recorded. Those bodies are described as spherical, papillate, and from 8 

 to 10 microns in diameter. They are said to cohere in grapelike clusters, 

 and to form a brick-red mass within the bodies of the dead insects. Upon 

 germination in a nutrient solution they gave rise to septate germ tubes 

 which bore single, terminal, cylindrical, colorless spores measuring 9 by 3 

 microns. 



It is evident that the method of germination of the resting spores 

 described above does not coincide with analogous processes in the Ento- 

 mophthorales. Furthermore the brevity of the description served to 

 confuse rather than aid subsequent systematists who were inclined to 

 follow Krassilstschik in referring the organism to this family. 



Two years later Sorokin (77, 18), another Russian writer, found a pe- 

 culiar organism in the larva of a lepidopterous insect, A gratis segetum, 

 and, apparently unaware of Krassilstschik's work, described and figured 

 what is without doubt the same form, under the name Sorosporella 

 agrotidis. Sorokin 's figures are sufficiently complete and his description of 

 the resting spores sufficiently comprehensive to render an identification 

 possible and to indicate clearly that the form with which he was con- 

 cerned was identical with that previously described by Krassilstschik. 



The characteristic coherence of the resting spores in masses or aggre- 

 gations was recognized by both of these authors in naming the organism, 

 Krassilstschik expressing the condition by using the specific name 

 uvella, while Sorokin selected "Sorosporella" to designate his new genus. 



In 1889 Giard {8) called attention to the similarity of Tarichium uvella 

 Krassilstschik and Sorosporella agrotidis Sorokin, pointing out that the 

 characters of the two forms, such as the reddish-colored, powdery spore 

 mass, the peculiar coherence of the resting spores, and their measurements 

 (according to Krassilstschik, 8 to 10 microns; according to Sorokin, 4 to 7 

 microns) corresponded so closely that he believed them to be identical. 

 Giard, however, in agreement with the majority of mycologists at the 

 present time, held that the generic name Tarichium, of which the type is 

 T. megaspermum Cohn., should be confined, if employed at all, to those 

 species of Empusa and Entomophthora in which resting spores only are 

 known. As the resting spores of the form under consideration are en- 

 tirely unlike those of any known Empusa or Entomophthora, he proposed 

 that the generic name Sorosporella be employed together with the spe- 

 cific name uvella of Krassilstschik. Giard, however, while of the opinion 

 that the fungus should not be called Tarichium, adhered to the belief 

 that it should be placed in the Entomophthorales. 



