112 



being isolated and detached, and the circulation through them in- 

 terrupted or altogether annihilated, they are now unable to maintain 

 an independent existence, and their vitality becoming enfeebled, the 

 laws of chemical affinity are called into operation ; gases are gene- 

 rated in the interior of the cells, finally producing their rupture and a 

 decomposition of their contents. Thus, therefore, by the simple and 

 mechanical operation of the Fungus alluded to, is the destruction of 

 the fruit insured, and a satisfactory explanation afforded of the rapid 

 decay of certain fruits. 



But it may be asked, is not the Fungus to which allusion has been 

 made, an effect and not a cause of the decay ? I am of opinion, for 

 reasons presently to be stated, that it cannot be regarded in any other 

 light than as a cause ; not the only one, indeed, but as the principal 

 and exciting cause of the phenomena of the decay of fruits. 



All the causes, for there are several minor ones which concur ir* 

 producing decay in fruits, may be divided into the predisposing, the 

 exciting and the proximate. Among the predisposing causes may be 

 mentioned imperfect development of the fruit ; an over ripe state ; a 

 lax condition of the parenchyma or pulp ; and exposure to extremes 

 of temperature combined with moisture. The exciting causes are- 

 injuries, bruises or contusions, but above all, the Fungus or Fungi 

 spoken of: while the immediate cause is impeded circulation, which 

 brings with it the results above detailed. 



It will now be apparent that a marked analogy exists between mor- 

 tification occurring in the animal frame, and that form of decay in 

 fruits arising from the presence of a fungoid production, which fonn 

 may, indeed, with propriety, be termed vegetable mortification. The 

 causes of mortification in the animal, as well as in the apple, pear and 

 numerous other fruits, resolve themselves into predisposing, exciting 

 and proximate — the predisposing being peculiar habits and condi- 

 tions of body ; the exciting, injuries and exposure to extremes of tem- 

 perature ; and the proximate, interrupted circulation. The only dif- 

 ference in the two forms of mortification, consists in the manner in 

 which the circulation becomes affected in each : in the animal form, 

 it is the result of a vital process, inflammation and its consequences, 

 while in the vegetable form, it is the effect of the operation of a me- 

 chanical cause, or impediment to the circulation arising from the pre- 

 sence of the Fungus. 



In order to show how far the presence of the Fungus is necessary 

 for the production of decay in fruits, let us endeavour to explain the 

 phenomenon without reference to it. 



