ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
77 
which are given in the original. The vexed question of spore-formation 
is next discussed, and the authors reconcile contradictory observations 
by reporting that the various forms described are merely phases in the 
development of the clilamydospore. These bodies are developed at the 
end of a mycele, and are spheroidal cells with well-defined membrane, 
and, at first, finely granular contents. The contents soon aggregate to 
form a central body, surrounded by a number of highly refracting 
spherules. From the chlamydospores is developed the fungus, but the 
exact manner was not observed. The authors conclude their morpho- 
logical examination by pointing out that the thrush fungus cannot be 
ranked with the family of Saccharomyces, and that the determination of 
its exact position is not at present possible. 
The biological relations of Oidium albicans are considered under 
three divisions ; the first dealing with conditions associated with change 
in the form of the fungus ; the second with the influence of an acid or 
alkaline reaction of the medium ; and the third with the nutrition of the 
fungus. In the course of these researches some interesting facts were 
brought to light, e. g. the simpler the molecular weight of the food- 
stuff supplied — at any rate, as far as carbohydrates are concerned — the 
more suitable was this as a pabulum ; and the more complex the 
nutrient medium and its constituents, the more mixed did the vegetative 
forms of the fungus become. Cultivations constantly exhibited the 
tendency to retain their special characters for several generations. 
The most favourable reaction for the medium was a slightly alkaline 
one at starting. If too alkaline, growth was at first retarded, but after- 
wards accelerated owing to decomposition taking place in the medium. 
Slight acidity seemed to have no action on the growth, though too much 
acid stopped it. In any favourable conditions of growth the yeast 
form was predominant ; when the conditions were inimical, then the 
filamentous form occurred ; and, of course, there were many intermediate 
phases, called globoso-filamentous. The action of various gases and the 
effect of the absence of air on growth are exhaustively discussed. 
One of the methods of observation pursued deserves a passing 
notice. It was the same as that used by liaulin for Aspergillus niger, 
the principle of which is to weigh the results of crops of a pure 
cultivation obtained under definite stringent conditions. In this way 
the value of different nutritive media was appreciated. 
Pure Cultivations of Actinomycosis and its Transmissibility to 
Animals.* — Prof. M. Wolff and Dr. J. Israel have succeeded in making 
pure cultivations from a case of Actinomycosis hominis by sowing the 
granules on agar kept at 37° and devoid of air. Successful cultures on 
eggs, fresh or boiled for three to four minutes, were also obtained. 
Within and around the grains distributed over the agar surface are 
formed granulations, at first hyaline, but afterwards becoming opaque. 
On transferring the first cultivations to a fresh agar surface in three to 
five days numerous little granulations, resembling dewdrops, not larger 
than a pin’s head, make their appearance. These usually remain 
separate, but may become confluent. Though the microbe is undoubtedly 
* Virchow’s Archiv, cxxvi. p. 11 (8 pis.). See Annales de Micrographie, i v 
(1892) pp. 354-6. 
