1C8 



ROLAND THAXTER ON THE 



Conidia nearly spherical to short-ovoid, often with a short, truncate or commonly 

 slightly papillate base; with granular contents; without large fat globules, and slightly 

 smoky in color ; 15 X 18 /t -18 X 20//. Conidiophores simple, arising directly from small, 

 spherical hyphal bodies of a yellowish color. Gystidia not observed. Secondary co- 

 nidia of two kinds: the first like the primary, the second almond-shaped and borne 

 obliquely on capillary conidiophores. Resting spores, zygospores, elliptical or subovoid, 

 yellowish, becoming often smoky and opaque, formed by the conjugation of two small, 

 spherical hyphal bodies by means of slender gametes, above the point of junction of 

 which the spore rises as a bud; average measurements 30 X 19/,.. Host attached to sub- 

 stratum by the insertion of its proboscis. 



Hosts. Hemiptera: Aphis mali and very many other aphides. 



Habitat. Maine, Massachusetts, North Carolina, Europe. 



The name adopted above for this interesting species is that used by Nowakowski in 

 his Krakow paper 1 , although, to avoid confusion, it should be mentioned that the same 

 author in his review of this publication 2 uses the name ^Freseniana " by an apparent 

 oversight. The species is a very common one, having been found by Nowakowski on 

 numerous aphides and also recorded by Schroeter as belonging to the Silesian flora. 

 Although it has not been previously noticed in America, I have found it very common 

 at Kittery, Maine, in the vicinity of Cambridge and also as far south as Cullowhee, C, 

 where both the conidial and zygosporic forms occurred on an Aphis infesting Solidago. 

 At Kittery, a black Aphis on poppy, as well as the common apple Aphis, was found at- 

 tacked by F. Fresenii about the middle of June; and the last mentioned host contained 

 abundant zygospores even at this early date. I have found the same species on aph- 

 ides infesting Bidens and other plants about Cambridge as late in the season as the first 

 week of October; but here no resting spores occurred. The formation of the resting 

 spores, illustrated by the series of figures (127-140), has already been described in 

 some detail (p. 148). As far as can be determined from alcoholic or dried material, the 

 masses of protoplasm (figs. 106-108) from which the conjugating hyphal bodies are de- 

 rived, have no proper wall, a circumstance which has been previously noted by Sorokin 

 in connection with his E. colorata. Before reproduction commences, these protoplasmic 

 masses become divided, rolling themselves into small, spherical hyphal bodies (fig. 127 ), 

 which, when developing, certainly show the presence of a surrounding wall. This wall, 

 during the process of conjugation, becomes considerably thickened, so that the two hy- 

 phal bodies remain attached to the spore in the form of bladder-like appendages which 

 are tolerably persistent (figs. 135-138) . The zygospores, which have been hitherto un- 

 known, differ from all other described forms by their elliptical shape. In very mature 

 specimens, they are sometimes almost black and opaque, though I am unable to say 

 whether this is due to the absorption of coloring matter from the host; or whether, as 

 seems more probable, the resting spores may not assume a smoky color, analogous to 

 that of the conidia, which is deepened by age. 



The conidia are readily distinguished by their small size and smoky tint, as well as 

 by the peculiar almond-shaped secondary conidia of the second type, borne on slender, 



1 L c. B. 2 Bot. Zeitung, xl, p. 5G1. 



