ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 345 



selected by them for experiments which have lasted over three years. 

 In both species they have grown a series of diverse forms, conidiophores, 

 spermogonia, pycnidia, sclerotia, chlamydospores, and cysts. It has 

 further been proved by Klebahn that Glozosporium nervisequum has a 

 perfect ascosporous form, Gnomon ia veneta. The writers took spores 

 from the spermogonia of the fungus, and obtained, in sugar media, 

 generation after generation of yeast-cells. Under certain conditions the 

 cells became invested with an outer membrane and were brown in colour. 

 When the yeast was grown on an exhausted medium, endogenous spores 

 were formed. In G. ampelophagum there were formed 1, 2, or 3 spores, 

 somewhat ovoid in shape, which again formed yeasts in a sugar solution. 

 Exactly the same results were obtained with G. nervisequum, but in this 

 case the endogenous spores were more numerous, varying from 2 to 12. 

 Such results could not be obtained with other closely allied fungi. 



The formation of endogenous spores has been looked on as ascus- 

 formation, and has placed Saccharomyces among the primitive Asco- 

 mycetes. The results obtained by Viala and Pacottet throw considerable 

 doubt on this view. In the life-cycle of Glceosporium nervisequum there 

 would thus be two very different stages of ascus-spore formation. The 

 view of Pasteur that Saccharomyces was at its origin a filamentous 

 fungus, has also had some confirmation, though possibly it has lost all 

 power of reverting to its original filamentous condition. 



Nuclear Division in Saccharomyces ellipsoideus I. Hansen.* — 

 Franz Fuhrmann sketches the work of previous authors on the nuclear 

 division of yeast-cells, and then gives the results of his own research. 

 He describes his methods of culture, fixing, staining, etc. The resting 

 nucleus is small with a delicate structure, and is often surrounded by a 

 clear zone, though sometimes that was not visible, and probably is only 

 a vacuole. In the preliminary stages of division the nucleus increases 

 somewhat in size, the chromatic substance becomes more condensed and 

 forms into chromosomes, evidently to the number of four. These are 

 seen to arrange themselves in the monaster stage ; splitting then takes 

 place, the daughter-chromosomes travel polewards, and a diaster stage is 

 reached ; the knot stage is reproduced, and finally a resting stage of each 

 daughter-nucleus. Budding of the cells follows at a later stage than 

 nuclear division, though sometimes the two acts are synchronous. The 

 nucleus may pass over into the new cell at the knot stage of the daughter- 

 nucleus or even earlier. A resting stage of both nuclei usually follows, 

 but a second karyokinesis of the nucleus of the mother-cell may take 

 place immediately. Fuhrmann found in his preparations no evidence 

 that any fusion of nuclei took place in the cell previous to nuclear 

 division representing, according to Hirschbruch, a sexual act. Figures 

 are given of the different stages of division. 



Toxin of Aspergillus fumigatus.t — E. Bodin and L. Gautier have 

 found that this fungus produces a toxic substance bearing a strong 

 resemblance to bacterial toxins It reacts on the nervous centres, 

 causing convulsions and proving fatal in a short time, or, if the dose is 



* Centralbl. Bakt., xv. (1906) pp. 710-17 (1 pi.). 

 t Ann. Inst. Pasteur, xx. (1906) pp. 209-24. 



