10 



Neverllieless, these forms are so Avide-spread, that a great number 

 of the spores of these moulds undoubtedly reach the digestive 

 apparatus daily. As the discrimination, wliich allows some species 

 to pass the ahmentar}^ canal alive while others are killed, must 

 take place withiii the body, we have to consider for a moment the 

 discriminating factors which influence the fungous spore while on 

 its passage through the body of warm-blooded animals. Three such 

 factors present themselves: temperature, the action of gastric and 

 intestinal juices, the combined action of temperature and gastro- 

 intestinal juices. 



The relation to temperature of the fungi isolated from the alimen- 

 tary tract of man and warm-blooded animals has alredy been dis- 

 cussed. They all grow vigorously at 37^ C, that is, at blood-tem- 

 perature. Any inhibitory effects of the body-temperature on these 

 forms are, therefore, out of question, and only the relation to blood- 

 temperature of forms with a lower optimum temperature than 37" 

 C, becomes of interest to us in this connection. 



Most of the species of Aspergilhis and Penicillium, indeed, all of 

 those forms which one would expect to find in the faeces, have an 

 optimum temperature considerably lower than 37^ C. Aspergilhis 

 glaucus is greatlj' retarded in its growth at 37" C. (Wehmer 

 67). Pemcilliiim commiine, P. roqueforti and P, camemberti do not 

 show any growth at all at this temperature (Thom 63). Only 

 relatively few, however, are actually killed at 37^ C. Among these 

 are P italiciim and P. digitatum (Thom 63, Westling 70). As a 

 rule the vitality of the spores of the green species of Penicillium is 

 not destroyed b}^ being exposed to a temperature of 37° C. for a 

 shorter time. Spores of Penicillium freqnentans, isolated from frog 

 and incubated for 48 hours at 37" C, invariably germinated when 

 brought into room temperature. Camurri (4) found that the ger- 

 minalion power of »P. glancum» was set back when kept at 37" 

 C, but completely destroyed by prolonged exposure of the spores 

 to this temperature. Tiraboschi (65) found that spores of »P. glan- 

 cum», incubated at 37" C. first lost their vitality after 15 days. 

 Qnly very few germinated after having been incubated a month, 

 and these w^^ere delayed a couple of days in their germination. 



The evidence on this point is conclusive and shows that the 

 temperature alone cannot be the decisive factor that brings about 

 the destruction of fungous spores during their short detention in 

 the alimentarj^ canal. Even if growth is suspended or the germi- 



