115 



much longer than any of the others, and which is, in fact, to be re- 

 garded as the stem of the plant, of which there are usually many thou- 

 sands in a single decayed apple or pear. During these three stages 

 of their growth, the Fungi are wholly within the body or mesocarp of 

 the fruit, and have usually no direct communication with the external 

 atmospheric air, from which they are separated by the epicarp or skin; 

 but in their fourth and final condition, a portion of each Fungus be- 

 comes external, and they can only become so when either the skin 

 has been ruptured by violence, or deteriorated by the process of de- 

 composition. This external portion is the proper plant, and consists 

 of a long stem, bearing at its extremity the reproductive portion of 

 the plant, which assumes various forms indicative of the species. The 

 ramified filaments therefore, which are the first parts formed, are the 

 roots, or organs of nutrition of the Fungi. Now, I have no doubt 

 whatever, that the external portions of the majority of those Fungi 

 which develope themselves on the surface of fruits, have been figured 

 and described ; but their internal relations and effects, so far as I am 

 aware, have escaped notice : and these appear to me to be exceed- 

 ingly interesting. 



Two enquiries of much interest still demand our consideration : — 

 the first relates to the manner of the entrance of the Fungi within the 

 fruit ; the second, to the cause which determines the precise period of 

 their development. 



There are two ways in which I conceive it possible that the sporules 

 of the Fungi might have gained admission into the fruit, or, what is 

 nearly the same thing, into the fruit-tree : — either by the stomata on 

 the surface of the fruit and plant ; or by means of the roots, the soil 

 containing the reproductive bodies, the presence of which in it being 

 accounted for by the decay of fruit on the earth beneath the tree. 



The causes which determine the precise period of the development 

 of the Fungi, are involved in mystery almost as impenetrable as those 

 which regulate their reproduction. They would appear, however, to 

 be, — injury to the fruit, its condition, and variations of temperature, 

 especially combined with moisture ; the latter being a predisposing, 

 and the two former, exciting causes of development : although the 

 exact manner in which injury to fruit acts, as such, is not very clear, 

 but is possibly thus. The injury to the fruit occasions the rupture of 

 some of the cells of the parenchyma, and the effusion of their con- 

 tents ; a decomposition is brought about, amidst which the Fungi 

 find the combination of circumstances essential to their growth and 

 sustenance. 



