232 
J. Ramsbottom, 
normally uninucleate those of Rhizopus nigricans and Phycomyces 
nitens plurinucleate. Studying the segmentation of the protoplasm in 
the sporangium Moreau found that in C. conica, R. nigricans and 
P. nitens , species with plurinucleate nature spores, irregular vacuoles 
separate fragments of protoplasm which, after the formation of a mem¬ 
brane, become spores. Their separation gives the impression of a retraction 
of the protoplasm. They form masses of amoeboid appearance joined by 
trabeculae which become thinner and break. In Mucor spinescens (and 
possibly A. glauca) the protoplasm becomes vacuolate and takes the 
form of elongated threads enclosing the nuclei. The thread nips off into 
the usually uninucleate spores. 
In Cunninghamella echinata and C. Bertholletiae the swelling 
which supports the conidia arises as in the above cases. The protoplasm 
separates into two layers the exterior portion of which contains denser 
protoplasm and more numerous nuclei. Small swellings with narrow 
sterigmata arise and the nuclei from the peripheral layer pass into these 
conidia which enclose from three to eight at maturity. “Au bien de 
constituer des spores à Finterieur de la tête renflée, le protoplasma 
et les noyaux forment des conidies à la périphérie.” 
Much discussion has taken place as to whether Piptocephalis , 
Syncephalis and Syncephalastrum (Cephalideae) should be considered 
as having conidia or sporangia. Moreau studied Syncephalastrium 
cinereum and 5. racemosum. The sporiferous head arises in the manner 
of a sporangium. Tubes bud out around the swelling. Into these the 
nuclei pass sometimes to the number of twenty. Often the protoplasm 
of the tube differentiates into two layers. The spores arise by the con¬ 
densation of the protoplasm around the nuclei. Each spore contains 
usually one nucleus but may contain several, and surrounds itself with a 
cell wall. The formation of spores “doit être décrite comme une pro¬ 
duction de spores internes à l’intérieur d’une sorte de sporange allongé;. . . 
le sac qui les produit n est pas non plus un véritable sporange homologue 
de celui des Mucor”. 
The results of the study of zygospore formation in twelve species 
is given. Mucor genevensis (heterogamous, heterothallic), Absidia spinosa 
(heterogamous, homothallic), Rhizopus nigricans and Phycomyces nitens 
(isogamous, heterothallic) are the species not considered in the previous 
résumé 1 ). 
The two first agree with what was described by the author in other 
species of the same genera. Phycomyces nitens is, like Sporodinia 
grandis , unfavourable for study. Multiple nuclear fusions were, however, 
clearly observed in the zygote. The account of R. nigricans differs 
greatly from that given by Me Cormick. There is no coenocentrum 
present. Most of the nuclei arrange themselves in pairs and fuse, a few 
only degenerate. Moreau’s account is consistent. The zygospore in all 
cases results from the fusion of two multinucleate gametangia. Mitotic 
divisions of the same type as those in the mycelium occur in the young 
zygospore. The nuclei then fuse in pairs or degenerate. In all cases 
studied except Zygorhynchus Dangeardi the fusions preponderate and 
1) The Mucor sp. (Mycol. Centralbl. 1912, 1, p. 204) is now identified as M. 
silvaticus. The two unnamed species of Zygorhynchus are regarded as new species, the 
one with only four functional nuclei being called Z. Dangeardi , the other Z. Bernardi. 
