l6o DIVISION II.— COURSE OF DEVELOPMENT OF FUNGI. 



The Entomophthoreae do not live exclusively on insects. Completoria complens, 

 which according to Leitgeb's observations is one of the group, is a small parasitic Fungus 

 in the cells of the prothallia of ferns. Leitgeb's account of its structure, of the formation 

 of its gonidia on the extremities of branches which have emerged from the cells of its 

 host, and of its rcsting-spores, agrees almost exactly with these features in Empusa and 

 Entomophthora. Brefeld also 1 has recently reported an allied species, which he found 

 parasitic on some Trcmellineac, and names Conidiobolus utriculosus. 



Literature of the Entomophthoreae. 



F. Coiix. Empusa Muscae und d. Krankheit d. Stubenfliegen (N. Act. Acad. Leop. 



XXV, pars I, 1855). 



S. Lebert, Die Pilzkrankheit d. Fliegen (Verh. d. Naturf. Ges. z. Zurich, 1856). 



G. Fresenius, U. d. Pilzgattung Entomophthora (Abh. d. Senkenb. Ges. II, 1858). 



O. Brefeld, Unters. u. d. Entw. d. Empusa Muscae u. E. radicans (Abh. d. Naturf. 

 Ges. z. Halle, XII, 1873). 



F. Cohn, Ueber eine neue Pilzkrankheit d. Erdraupen (Beitr. z. Biolog. d. Pflanzen, I, 

 1874, p. 58). 



L. Nowakowski, Die Copulation einigcr Entomophthoreen (Bot. Ztg. 1877, p. 217). 



BREFELD, Schimmelpilze, IV (1873), p. 97 ; — Id., Hcfepilze, 1. c. 



H. LEITGEB, Completoria complens, ein in Farnprothallien schmarotzender Pilz 

 (Sitzungsber. d. Wiener Acad. 84, Abth. 1, 1881). 



M. SOROKIN, Zwei neue Entomophthora-Arten in Cohn's Beitr. z. Biol. II, Heft 3. 



A. Giard, Deux especes d'Entomophthora, &c. (Bull. sc. du depart, du Nord, ser. 2, 

 annee 2, No. 11, p. 253). 



L. Nowakowski, Entomophthoreae (Abh. d. Acad. d. Wiss. z. Krakau, 1882, (Polish). 

 Report on the same in Bot. Ztg. 1882, p. 560. 



CHYTRIDIEAE. 



Section XL VI. This is the name for what has gradually become a very varied 

 series of small microscopic forms, which spend their entire vegetative period, or at 

 least a definite stage of their spore-producing time under the water, and agree 

 morphologically in forming swarm-spores in sporangial cells of a fixed and definite 

 shape; each swarm-spore has usually one cilium, and developes either directly or 

 through inconspicuous transition states into fresh sporangia] cells. Resting-spores 

 are also known in certain species, and these develope directly in germination into 

 sporangia or produce them after a short intermediate stage. There is such great 

 similarity in the formation of sporangia and swarm-spores, that the species composing 

 the group have always, one may almost say instinctively, been considered to be closely 

 related to one another. Vet our knowledge of the several species is so unequal, and 

 the course of development in the best-known forms is so different in extreme cases, 

 and these extremes are so imperfe< tly connected by the intermediate forms with which 

 we are acquainted, that we musl ai present feel in doubt whether we are dealing in 

 this case with a series of objects naturally related to one another, or with a number of 

 groups of similar adaptation and therefore of similar form, but of different natural 



1 Hcfepilze, p. 10. 



