CHAPTER VII.—PHENOMENA OF VEGETATION.—PARASITES, 377 
fresh spores also are sown in nutrient solutions the germ tubes which are at once 
emitted develope only mycelia producing spores in the manner just described. In 
this respect, according to Grawitz, Achorion, Trichophyton, and Microsporon are 
exactly alike, but they differ from one another in size. This difference is attributed 
by Grawitz to differences in the food, which can no doubt give rise to great diversity 
of size in the same species, and he therefore considers the three forms as belonging 
to one and the same species; and he further identifies this species with Oidium lactis, 
partly on the ground of the resemblance of the three forms when grown in a nutrient 
solution to Oidium, and partly because inoculation with pure Oidium will produce 
diseases of the skin which resemble a mild herpes. 
The view that these four forms belong to one another cannot on our part be 
summarily rejected, but at the same time it requires further proof. In any case the 
comparison with the Mucor which forms gemmae shows that those forms do resemble 
imperfectly developed states of other known species of Fungi with typical gonidia and 
carpospores. Hence the question arises whether organs of this description are to be 
found also in skin-parasites. On the answer that may be given to this question will 
depend the determination of the special qualities of these Fungi as parasites. At 
present the question is still unanswered, though many attempts have been made to 
solve it in past times by means of artificial cultivation ; but Saccharomyces, Penicillium, 
Eurotium and all sorts of Moulds made their appearance in the impure material used 
for these experiments, and then the skin-parasite was introduced in one. way and 
another without reasonable ground into the cycle of forms of these species, as 
Peyritsch long since clearly showed. 
It has been proved by experiment that Saccharomyces albicans, Reess 
(Oidium albicans, Robin) causes a formation of pustules and scab, known as thrush or 
aphthae, on the mucous membrane of the mouth, throat, and oesophagus especially in 
young individuals. Grawitz and Reess' have recently shown that the plant is a 
form of Sprouting Fungus with long cells resembling Saccharomyces Mycoderma ; 
its ascospores have never been observed ; it does well as a saprophyte, but excites 
weak alcoholic fermentation in saccharine solutions and is therefore a facultative 
parasite. It has yet to be determined whether it is identical with S. Mycoderma 
(the flowers of wine) or with some similar form. 
Section CVII. The name of Actinomyces Bovis has been given by Harz to 
a remarkable growth discovered by Bollinger and Israel which occurs in peculiar 
swellings on the jaw-bone, especially in cattle, and is in causal connection with them, 
but is also found inside certain parts of the body in pigs and men ?. In the swelling, 

1 Grawitz in Virchow’s Arch. 70, p. 566, and 73, p. 147.—Reess, Ueber d. Soorpilz (Sitzgsber. d. 
Phys. Med. Ges. zu Erlangen, 9 Juli 1877 and 14 Jan. 1878). The literature of the subject 
is given by Kehrer, Der Soorpilz, Heidelbg. 1883. 
2 Bollinger, Ueber eine neue Pilzkrankheit beim Rinde (Centralbl. f. med. Wiss. 1877, Nr. 27). 
J. Israel, Neue Beob. v. Mycosen d. Menschen in Virchow’s Arch. 74 (1878), and 78. 
O. Harz, Actinomyces Bovis. (Deutsche Zeitschr. f. Thiermedicin, 1. Supplementheft (1878), 
p- 125). See also in the same publication, p. 45. 
E. Ponfick, Die Actinomycose d. Menschen, Berlin 1882. 
Johne, Die Actinomycose (Deutsche Zeitschr. f. Thiermedicin, VII, (1882), p. 141, tt. 8-10). 
Pusch, Ueber Lungenactinomycose (Arch. f. wiss. u. pract. Thierheilkunde, IX (1883), p. 447). 
In this paper the different works on the subject are most fully enumerated. 
