286 THE LOWER FUNGI— PHYCOMYCETES 



the beak and divides there by mitosis. One of the daughter 

 nuclei in each beak then passes back into the parent cell, the 

 beaks are cut off by septa, and the nuclei remaining in the beaks 

 disintegrate. One of the parent cells then enlarges until it 

 becomes many times the size of the other, and the septum 

 between the cells in part disappears leaving a large pore. The 

 nucleus of the smaller cell accompanied by the cytoplasm passes 

 through the pore, and in the larger cell the two nuclei soon lie 

 together and seem about to fuse. In some cases they may do 

 so, but in others they seem to undergo a final division, after 

 which one daughter nucleus in each case disintegrates and the 

 remaining pair fuse. The combined cytoplasm of the two cells 

 finally contracts about the fusion nucleus, forming a resting 

 spore which at maturity is thick-walled and lies free in the 

 larger cell. In several respects this process of sexual spore 

 formation recalls that of the Oomycetes, and the spore might 

 easily be regarded as an oospore. However, it is termed a 

 zygospore in all the literature, and the characters of the asexual 

 stage indicate clearly that the fungus belongs to the Zygomycetes. 



The life history of the other species, B. myxophilus is very 

 imperfectly known. 



The genus Ichthyophones Plehn and Mulsow containing several 

 species isolated from the intestinal tract and excrement of fish 

 is very closely related to Basidiobolus, if not in fact actually 

 identical with it. This is strongly indicated by figures published 

 recently by Leger (1927) for /. intestinalis Leger & Hesse. 

 The presence of globose uninucleate cells in the alimentary 

 canal of the fish affords a point of striking similarity between 

 the two genera, and may indicate a comparable life cycle. 

 2. Conidiobolus Brefeld (1884: 37; also see Schroter 1889: 224). 



In this genus the mycelium when young is profusely devel- 

 oped, consisting of richly branching, many-septate threads. 

 Later irregularly swollen or lobulated portions are put out, 

 and these, shortly before conidiophore formation, break apart 

 at the septa to form irregular hyphal bodies. The conidiophores 

 are unbranched. They arise from the hyphal bodies, and cut 

 off apically large solitary conidia which are discharged violently 

 as in Empusa. 



The genus was founded by Brefeld on C. utriculosus Brefeld 

 and a smaller-spored form, C. minor Brefeld, both occurring on 

 the fruit body of Auriadaria as parasites or facultative sapro- 



