148 MASSACHUSETTS HORTICULTURAL SOCIETY. 



"we should naturally infer that, since nature always does her best 

 to heal wounds, it must be because the plant would otherwise 

 suffer. Experience certainly shows that open wounds are danger- 

 ous in plants as they are in animals, although I Avould not go so 

 far as to say that they are inevitably dangerous. There is no 

 •doubt, however, that in most cases they are dangerous. Every 

 surgeon recognizes the dangers attending open wounds in animals, 

 and, before the days of the antiseptic treatment, the dangerous 

 and often fatal results of operations were due in many cases to 

 the entrance of germs from the air into the system through open 

 wounds. In the same waj^ wounds of plants are dangerous, 

 although a fatal result may not be reached before the expiration of 

 several years. Naturally the intact epidermis of the younger 

 parts of plants and the corky bark of the older branches and 

 trunks prevent the access of the spores and mycelium of fungus 

 parasites to the more sensitive tissues beneath. Where the bark 

 -has been removed, they may and often do work their way into the 

 interior, and cause, at first, a local and, later on, a general decay 

 of the trunk. The fungi which are the agents of destruction in 

 such cases are not the rots, smuts, or mildews, which affect rather 

 herbaceous plants than trees, but fungi of the toadstool family. 

 Those of 3^ou who have watched the larger wounds of trees must 

 have often seen clusters of toadstools of different kinds growing 

 out of the wounds. They are most frequently seen in the warmer 

 mouths, but there are a few species which are to be found even in 

 the mild weeks which sometimes come in midwinter. Besides the 

 fleshy toadstools there are many species of punk-fungi, belonging 

 technically to the same family as the toadstools, which infest 

 wounds, and they are so tough aud hard that they can be found 

 throughout the year. 



The question might arise Avhether these toadstools aud punk- 

 fungi grow in wounds because the exposed wood is already dead 

 and therefore furnishes food for the fungi, or whether, on the 

 other hand, the death and decay of the wood are brought about by 

 the presence of the fungi. In a certain sense both these questions 

 may be answered in the athrmative. When the exposed wood 

 dies, it furnishes a soil in which the spores of the toadstools aud 

 punk-fungi can germinate and grow, and it is also true that when 

 they have once begun to grow, many species are able to make 

 their way dowjiward and upward into the health}' parts of the 



