117 



inoculation of the sound fruit with a portion of decayed matter, 

 containing filaments of the Fungi. 



Although it might safely be concluded, by the light of reason, that 

 if the Fungi were really the cause of the decay, they would repro- 

 duce this decay, when introduced into sound fruit ; — yet I was 

 hardly prepared for the marked and rapid changes which fruit thus 

 inoculated undergoes. In twenty-four hours from the introduction of 

 the decayed matter, if the apple or pear employed in the experiment 

 be at all of a soft consistence, the effects become manifest ; a softness 

 and discolouration taking place around the spot which contains the 

 decayed fruit, mixed up with minute filaments of the Fungi; and this 

 softening and discolouration will often extend, in the course of three 

 or four days, over more than an inch of the circumference of the apple 

 or pear, progressing unceasingly until it has involved the entire fabric, 

 the decay developing itself in exact correspondence with the growth 

 of the fungi, so that in a few days, or weeks, a complete disorganiza- 

 tion of the fruit is effected by the silent and unperceived operation of 

 an agent, apparently weak and insignificant, but which annually de- 

 stroys vast quantities of various descriptions of fruit. 



It signifies but little what be the decayed matter used for this inocu- 

 lation, provided the filaments of the Fungi be present in it. So that 

 if we inoculate an apple w r ith a portion of decayed pear, the result of 

 the experiment will be the same as it would have been had the decay- 

 ed material been of the same nature as the fruit inoculated ; and we 

 may use with success the sporules of such Fungi as are observed 

 to develope themselves on the surface of injured fruit, but in this 

 case, the decomposition does not set in so quickly, requiring many 

 days to elapse before any very decided change is visible. In order 

 to ensure the success of the trial of inoculation, it is advisable to 

 raise lightly the epidermis of the fruit, the subject of the experiment, 

 and remove a small portion of the parenchyma, supplying its place 

 with the decayed matter. 



In the communication already referred to, it was suggested that the 

 sporules of the Fungi might have entered the fruit, either by the 

 stomata on its surface, as well as those of the tree generally ; or, by 

 the termination of the root, the soil containing the reproductive bodies. 

 It is manifest, however, from the fact that a simple bruise, which does 

 not impair the integrity of the epidermis of the fruit, has, but in one 

 instance in which I have made trial, given rise to decay ; and that 

 sound fruit, the cuticle of which has been ruptured, if kept from de- 

 cayed fruit, is long in becoming affected, while that w T hich is placed 



