112 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Saccharomycetes by the filiform spores, each asciis containing eight of 
them. 
Insects and Yeasts.* — Dr. A. Berlcse has made numerous investi- 
gations on the manner in which some insects, ants and flies, contribute to 
the diffusion, preservation, and multiplication of alcoholic ferments. By 
placing ants in a bottle connected with others the contents of which 
had been sterilised, it was shown that ants carried about them the germs 
of yeasts and moulds. From experiments made by exposing sterilised 
meat to flies, it was found that the quantity of yeasts carried by flies is 
about 26 times as great as that carried by the air. By inducing flies to 
visit sterilised grapes, these grapes were infected with S. apiculatus, and 
also with S. pastorianus and ellipsoideus and moulds. Though insects 
cany germs on their legs and feet, these germs are more abundant 
within their bodies, as was shown by a study of the excrement of meat 
flies and cellar midges ; and not only are they more abundant, but they 
actually multiply. Thus a droplet of must containing about 500,000 
S. apiculatus was given to a fly which eventually produced about 
35,000,000 of these yeast cells. Moreover, it was further found that the 
conditions inside the intestine of insects greatly influence the develop- 
ment of the different yeast germs ; for if an insect was fed on a mixture 
of S. apiculatus and S. mycoderma , the excreta at first contained both 
yeasts in about equal quantity ; then after a time S. apiculatus gained 
the ascendancy ; but if the insect were made to fast, S. mycoderma rapidly 
gained the upper hand. It was also observed that the ingluvies or crop 
of insects secretes a syrupy fluid suitable for the preservation and mul- 
tiplication of yeast cells ; and this gives reason for believing that some 
yeasts may be preserved during the cold season by insects. It is inter- 
esting to note that in one experiment the ants died promptly from par- 
taking of the juice of sour grapes, a fact which is evidence in favour 
of the protective character of the acids in fruit juices before maturation. 
Schizosaccharomyces octosporus.f — In the course of some further 
observations on octosporus-yeast, Dr. M. W. Beijerinck remarks that the 
genus Schizosaccharomyces at present embraces three species, S. octo- 
sporus, S.pomhe ( tetrasporus ), and S. asporus (arrack yeast). The author’s 
recent observations show that S. octosporus is responsible for the presence 
in nature of two races, one a sporogenous, the other a non-sporogenous 
form, features which might lead to the supposition that these two forms 
had some remote connection with S. asporus and S. tetrasporus. The yeast 
used in the recent researches was isolated from figs and currants. By care- 
ful separation of the ascospores from the vegetative cells, and after having 
been cultivated under definite conditions of environment on wort-agar 
(plates or tubes), it was found that when perfectly ripe, i.e. when the 
medium was exhausted, the colonies were of three kinds : — (1) white, con- 
taining only asci and ascospores ; (2) brown, comprising only vegetative 
cells and ascoid cells ; (3) pale brown, consisting of all three elements. 
On further cultivation of the brown colonies, there was constant repro- 
duction of non-sporogenous cells. While the white colonies reproduced 
* Rivista di Patologia vegetale e Zimologia, 1897. See Nature, lvi. (1897> 
pp. 575-7. 
t Centralbl. Bakt. u. Par-, 2 e Abt,, iii. (1897) pp. 449-55, 518-25 (2 pis.). CL 
this Journal, 1894, p. 602. 
