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 1 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 2 . 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 Jtdi 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, I. 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. 



