125 



which gradually extends itself over the surface of the fruit, and does 

 not at once involve its entire substance and fabric. All that Liebig's 

 theory can do, is to supply an explanation of the cause of the exten- 

 sion of decay after the direct introduction of decayed matter ; and 

 this only provided the fruit inoculated no longer possessed vitality. 



I showed also in the communication referred to, that the mere bruis- 

 ing of the parenchyma of the fruit, or its exposure to the contact of 

 air, would not in itself give rise to decay; and thus, having been un- 

 able able to find any sufficient cause which would explain all the 

 phenomena of decay in fruit, I was then compelled, as I am at pre- 

 sent, to have recourse for a satisfactory explanation to the operation 

 of entophytal Fungi. At the same time, I fully recognized the exis- 

 tence of a second form of decomposition in fruit, this being compa- 

 ratively of rare occurrence, and the result of the operation of chemical 

 affinities, vitality having ceased. To this form the views of Liebig 

 may, perhaps, with propriety, be applied in some cases. 



Since the last meeting of the Society, I have repeated the experi- 

 ment of inoculating fruit with the sporules of the Fungi, and with 

 the same success which attended the former experiment ; but I have 

 failed in inducing decay in sound fruit, by the introduction of de- 

 cayed matter destitute of Fungi in any state. Not, however, but 

 that this effect might ensue in some cases in which the vitality of the 

 fruit was either totally destroyed, or at all events much enfeebled ; 

 but were it an invariable consequence of its introduction, this would 

 not in any way affect the truth of the statement made relative to the 

 independent power possessed by Fungi in originating decay : and even 

 if they were proved not to do this, they would still be of as much im- 

 portance in a practical point of view as ever, since when inserted into 

 fruit which is undergoing spontaneous decay, these insidious destroy- 

 ers will produce marked and rapid effects, and speedily ensure its 

 complete destruction. 



In conclusion I may state that the apples employed in the two ex- 

 periments were of an exceedingly firm description ; and that an equal 

 number was inoculated with the sporules and with decayed matter.* 



* In the ' Annals and Mag. of Natural History ' some further observations will be 

 found in proof of the powers possessed by Fungi in destroying the living and healthy 

 vegetable fabric. In this communication it is stated that the " thallus " of a minute 

 Fungus was introduced into different portions of various kinds of vegetables, in all of 

 which decay was induced by its development, the extent of injury being greater or less 

 according as the plant subjected to the experiment was of a cellular structure, or 

 otherwise. 



