ZOOLOGY AND BOTANY, MICROSCOPY, ETC. HI 



identification, is described under the name of B. fallax. Morpho- 

 logically the bacillus resembles B. oRdematis maligni, but spores are not 

 observed in pathological exudates, nor are they found in glucose or 

 glucose-free media even after several months' incubation. The organism 

 is feebly motile in young cultures, but is actively motile in serous 

 exudates. It possesses numerous flagella (twenty or perhaps more) 

 which are very long, sinuous and spiriliform. B. fallax is a strict 

 anaerobe and is an active gas-producer. The cultures, unlike B. mdematis 

 maligni, do not possess a putrid odour, but have an acid smell resembling 

 B. perfringens. The organism has been found to be pathogenic for the 

 guinea-pig and the mouse, but not for the rat. 1 c.cm. of culture in 

 intravenous injection kills the guinea-pig in ten to sixteen hours ; 

 0-25 c.cm. in twenty to thirty hours. Following subcutaneous inocula- 

 tion the muscles become hypersemic, and are infiltrated with bubbles of 

 gas, while a gelatinous oedema extends over the entire abdomen. The 

 visceral lesions resemble those provoked by infection with B. adematis 

 maligni. An agglutinating serum with a titre of 3-^ has been prepared 

 by subcutaneous injection of rabbits with killed cultures of the bacillus. 

 The serum has no agglutinating action on B. mdematis maligni, B. mdema- 

 tiens, or B. perfringens, nor is the organism itself agglutinated by anti- 

 sera homologous with the latter organisms. 



Heterogamic Conjugation observed with a New Yeast : Zygo- 

 saccharomyces Nadsonii.* — -A. Guilliermond has identified a new 

 species of yeast, Zggosaccharomyces Nadsonii, which he has isolated 

 from a decoction of bitter orange peel which showed active fermentation. 

 This new yeast is of peculiar interest as, in common with two previously 

 described genera, Delaryomyces and Nadsonia, it exhibits true hetero- 

 gamy. At the moment of conjugation the yeast-cells are rounded in 

 shape, and possess one to three small buds, which are still united to the 

 parent-cell, the conjugation being effected between the parent-cell and 

 one of the buds. The mother-cell plays the part of the female gamete, 

 whilst the biid plays the role of the male gamete. The two cells are 

 united by a copulatory canal formed by the fusion of the two extruded 

 processes. The contents of the male gamete emigrate into the female 

 gamete, which then transforms itself into an ascus, generally enclosing 

 two rounded ascospores, whilst the remains of the male gamete is re- 

 absorbed. In some cases the contents of the two gametes mingle in situ 

 without the emigration of the male element. In this case the unequal 

 masses are united by a narrow isthmus, each portion containing an 

 ascospore. This phase is a transition between iso- and heterogamy. 

 This method of conjugation differs from that previously described by 

 the author in the case of Zygosaccharomyces chevalieri, in which the male- 

 functioning cell is completely separated from the female cell before 

 conjugation. 



Dysentery in the Argonne.f — P. Remlinger and J. Dumas have 

 investigated a series of cases of dysenteric infection occurring among 



* C.R. Soc. Biol. Paris, Ixxviii. (1915) pp. 568-70. 

 t Ann. Inst. Pasteur., xxii. (1915) pp. 498-519. 



