198 VEGETABLE PAEASITES. 



from the proper mucous membrane. Robin is of opinion that 

 the fungus grows in the layers of the mucus which are attached 

 to the epithelium, and on the surface of the latter; an opinion 

 which was refuted by Reubold. The mucous membrane is rarely 

 altered by the fungus, although it penetrates down below the 

 first epithelial layer, sometimes even into it, which leads to its 

 softening and ulceration, occurring especially on the alveolar edge 

 of the skin, when the fungous layers have been forcibly torn off. 

 It is as yet undecided, it seems, whether the fungi cannot live 

 on those places, or whether they thrive but sparingly, where there 

 is ciliated epithelium, although there seems to be no further 

 doubt that those tissues greatly favour the growth of the 

 fungus, which are covered with pavement epithelium. Berg 

 states, that this fungus does not occur around the rectum 

 and nates, arid on the nipple, but thinks that it may occur on 

 the mucous membrane of the genitals. Berg was chiefly led to this 

 statement by his theoretical speculations, and the former is there- 

 fore not yet decided. Further and final practical observations will 

 be required, which demand great care on account of this disease 

 being easily confounded with hsemorrhagic erosions of the stomach, 

 follicular affections, and ulceration of the intestinal tube in 

 children, or with undigested coagulated milk. 



Circumstances favorable to the development of the thrush-fungus, 

 according to Reubold. This fungus is found at every age, 

 the earliest as well as the oldest in preference, the reason of 

 which may, perhaps, be sought in the long sleep of very young 

 and of aged persons, leaving to the spores time for growth 

 without disturbance. Reubold observed it on persons from the 

 age of two days to seventy years, more especially, however, up to 

 the first nine months, frequently in connection with catarrh of 

 the bowels, from whatever cause produced. The conditions under 

 which the fungus thrives are little known. Secretory changes 

 of the mucous membrane (production of an acid secretion, parti- 

 cularly of lactic acid), induced and fed by the fungus, (Robin) ; 

 next to this a changed vegetation of the epithelium play still a 

 considerable part in the theory of the genesis of the fungus. Such 

 opinions are not fully proved yet. It is true that the thrush- 

 fungus, like the other fungi, is found to follow a decomposition 

 which provides for its wants, increasing it even by the eagerness 

 with which it abstracts nourishment. Decomposition of organic, 

 especially nitrogenous, substances, such as takes place in the 



