ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 479 



sporidioles in fungi, particularly in Discornycetes. The role which they 

 play in germination is important, for they act as food for the young 

 mycelium. A description is given of the appearance and common 

 variations of these guttulae. Boudier considers that they are very useful 

 in helping to distinguish between closely allied genera and species. The 

 spores must be fresh when examined. In some cases there is difficulty 

 in ascertaining whether a spore is septate or verrucose owing to these 

 appearances being simulated. Iodine solution can be used to dissolve 

 the oil when such is the case. 



West African Yeasts.* — A. Guilliermond describes five new species 

 of yeasts, Saccharomyces Chevalieri, S. Mangini, S. Lindnerii, Lygosac- 

 charomyces Chevalieri, and Mycoderma Chevalieri, from West Africa. 

 Full accounts are given of the forms and dimensions of cells, temperature 

 limits of budding, sporulation, macroscopic appearance in solid media, 

 action in presence of sugar, etc. The characters which distinguish the 

 three species of Saccharomyces are tabulated. Zygosaccharomyces 

 Chevalieri possesses a heterogamic copulation which precedes ascus 

 formation. Notes are given on the affinities of the species and their 

 special biological characters. 



Morphology and Cytology of the JJcidium Cup.f — F. D. Fromme 

 finds that the essential features in the development of the secidium cup 

 in the Uredineae are similar to those found in the development of the 

 caeoma. The primordium is formed by hypha? growing radially toward 

 the centre of the cup. The cup is, however, the more deeply seated 

 and produces a greater number of sterile cells and gametes to each 

 gamete-bearing hypha, The gametes form a fertile layer two or more 

 cells in thickness. The sterile cells that form the pseudoparenchyma of 

 the cup are homologous with the " buffer " cells of the caeoma. Sexual 

 cell fusions, by the breaking down of the cell walls between two equal 

 gametes, were found in Uromyces Caladii, Puccinia Claytoniata, 

 P. Violse, P. Hydrocotyles, P. Eatonise, and P. angustata. No central 

 organs (" fertile hyphas ") or multinucleated cells were found. The 

 organization of the cup, therefore, is merely that of a remarkably 

 unified colony of gametophores. Triple cell fusions were observed in 

 P. Claytoniata and P. Violse, and trinucleated aecidiospores were 

 frequently found in both these species and in U. Caladii. Several 

 quadrinucleate a3cidiospores and a chain of quadrinucleate cells were 

 found in P. Glaytoniata. The first fusion cells are formed at the centre 

 of the gametic tissue, and the subsequent ones are formed on all sides 

 of this centre in centrifugal order until the lateral borders of the 

 pecidium are reached. The fusing cells may have their long axes in 

 general in the long axis of the cup, but in P. Eatonise they are tangential 

 to its curved basal surface. Fromme holds that the presence or absence 

 of a peridium is a natural but not very fundamental distinction between 

 the aecidium cup and the cfeoma ; the production of a peridium is 

 correlated with the deep situation of the cup and the extensive formation 



* Ann. Sci. Nat.. s6r. 9 (1914) pp. 1-32 (5 pi.). 

 + Bot. Gaz., lvii. (1914) pp. 1-35 (2 pis.). 



