THE BEGINNINGS OF LIFE. 347 



germs fall upon suitable situations which are in a 

 condition favourable to their growth. Even here, how- 

 ever, the conjoint influence of predisposing and exciting 

 causes of disease must come into play. So that the 

 question is whether, in certain cases, the c predisposing' 

 causes may not be sufficiently potent to generate the 

 disease, without the aid of any c exciting ' cause in the 

 form of pre-existing Fungus-germs. Much evidence of 

 a general character, in addition to the many facts and 

 observations already alluded to, tends to favour this 

 view more especially in the face of the insuperable 

 difficulties which beset those who are exclusive advocates 

 of a c germ-theory.' 



In reference to the above-mentioned skin-diseases in 

 the human subject, Dr. Tilbury Fox l calls attention to 

 the fact of the extreme frequency with which the hair- 

 follicles are the seats of the first manifestation of the 

 morbid product ; and says that, for the most part, c the 

 very first spot at which any perceptible fungus can be 

 detected is a little way inside the follicles, near the 

 opening of the sebaceous glands.' Thence the fungus- 

 growth extends in various directions into the follicle 

 itself, into and upon the hair, and into the imme- 

 diately adjacent portions of skin. In other cases, as in 

 c chloasma,' it is the substance of the epithelial cells 

 over the chest or abdomen which is the seat of the 

 fungus spores and filaments. 



Certain altered states of secretion from the hair- 



1 ' Skin-Diseases of Parasitic Origin,' 1863, p. 43. 



