154 



ROLAND TIIAXTER ON THE 



down the distinction, as already mentioned. J$o definite line can be drawn, also, as con- 

 cerns the production of resting spores; since in species of the sphaerosperma type, which 

 must be placed in Entomophthora, we have exactly the same type of formation with that 

 occurring in E. apiculata, which it is equally necessary to place in Empusa. It is true 

 that conjugation is not known in Empusa unless it is represented in the very question- 

 able type described under E. Qrylli; yet it is unsafe to assume that it does not exist, or 

 that its absence is of generic value. The only consistent way out of the dilemma con- 

 sists either in considering all the forms under the tolerably coherent genus Empusa, or 

 in resorting to further splitting to express transitional forms. The sphaerosperma section 

 of Entomophthora, for example, shows decided differences from the rest of the group 

 in the character of its branching, in its conidia and secondary conidia as well as in its 

 formation of resting spores, and may, perhaps, with fuller knowledge of the species already 

 known or subsequently to be discovered, prove separable from the remaining forms. 

 Our knowledge of Empusae is at present in its infancy, and conclusions in respect to 

 subdivisions must be largely based on doubts; a foundation much more likely to pro- 

 duce confusion than a clear understanding of the group. 



The use of the name Empusa in preference to Entomophthora needs a word of expla- 

 nation, since the two have, until comparatively recent years, been used in the same sense 

 to designate entomogenous Entomophthoreae generally. Although an Empusa had been 

 previously described by Fries under an erroneous generic name (Sporendonema) , the 

 paper of Cohn 1 upon the "house-fly fungus" is the first in which the group was recog- 

 nized by a generic title, Empusa. This publication appeared in 1855, and in the follow- 

 ing year Fresenius,in an article 1 preliminary to his more extended paper on the subject, 2 

 pointed out that Empusa, having been preoccupied for a genus of orchids, should be 

 dropped, proposing Entomophthora in its place. A few months later Lebert, 3 taking the 

 same ground, proposed the name Myiophyton, over which the name of Fresenius of 

 course has priority. The two names have subsequently been used indiscriminately until 

 separated as two distinct genera by Brefeld and Nowakowski, who thus tacitly recog- 

 nized the validity of Empusa as a name; a validity also admitted by Cohn, Eidam, 

 Schroeter and DeBary who employ it without question. If therefore a single name is 

 to be used, Empusa certainly has priority and sufficient weight of authority to make its 

 use good. Asa matter of fact the orchidaceous genus Empusa is placed as a synonym 

 in Bentham and Hooker's Genera Plantarum, and seems unlikely to produce confusion 

 in any case. 



The position of the Entomophthoreae among the Zygomycetes is placed beyond a 

 doubt by the formation of the resting spores above described, yet it is interesting to note 

 that, until the publications of Nowakowski, and even subsequently, there has been much 

 difference of opinion concerning their true position; the weight of opinion assigning them 

 a place among the Oosporeae. The theory that the members of the group were merely 

 stages in the life-history of Saprolegniae, which has been maintained on a basis of actual 

 experiments as well as their supposed connection with the yeasts (Saccharomyces) , is 

 manifestly incorrect and a matter of historical interest only. In the latter case it is of 

 interest to note that species of Saccharomyces very frequently occur in connection with 



1 1. c. A. 2 1, c. B. 3 1, c. 



