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It is not to be expected that a botanist can go about the woods, microscope 

 in hand, peering with it into the minute nooks and crannies of trees to see if 

 there are any fungus spores germinating, but the process can easily be observed 

 by artificial means. The spores are so infinitely small they can only be examined 

 as transparent objects, and the easiest mode of seeing their germination is to 

 allow a few ripe spores to drop from a recently gathered and living fungus, on to 

 a small glass slide ; if this slide be at once put under the microscope, and the 

 spores kept warm and moist, they will germinate within twenty-four hours. As 

 glass does not afford them nourishment, the spores cannot of necessity go on 

 growing, but must perish after they have thrown out a few mycelial filaments. 

 One of the best and commonest fungi to experiment with in this way is Panus 

 stypticus, Fr. The spores of this species generally germinate in an hour or two. 

 After leaving the living parent, repeated breathing upon the glass slide greatly 

 aids germination. 



Again, if living spores are allowed to fall upon damp blotting paper, and 

 the paper is kept moist and warm, the spores will readily germinate ; to see 

 them, the blotting paper must be gently touched upon moist glass ; some of the 

 germinating spores will then be transferred from the paper to the glass, and 

 can be seen as transparent objects. Dark spores, especially the black, are the 

 quickest to germinate ; light spores, especially the white, are the slowest. From 

 my observations, I believe spores to be exceedingly short-lived ; some do not live 

 a single hour : the persistency and endurance resides in the mycelium. I believe 

 that most spores die very rapidly, after leaving the hymenium of the parent, 

 for this reason, that when I have allowed them to fall upon dry glass and they 

 have been exposed to dry air for a few hours, no efforts on my part to revive 

 them and cause them to germinate have been at all successful. 



When fungus spores have once alighted upon a suitable nidus, and thrown 

 out the mycelial threads, their destruction is by no means easy ; this mycelium 

 is neither destroyed by the heat and drought of summer, nor by the soddenirg 

 rains and frosts of winter ; it often exists under ground, or in trees, for years 

 without reproducing the parent fungus, owing to unfavourable combinations 

 of atmospheric and other circumstances. It is, however, very seldom utterly 

 destroyed, a well-known case in point being the almost insuperable difficulty of 

 destroying the mycelium of dry-rot (Merulius lacrymans, Fr. ) in timber. 



In giving a list of the larger Fungi peculiar to trees, two classes at once 

 present themselves to our notice : the first consisting of such as are altogether 

 peculiar to, and never found off certain trees ; the second being a cosmopolitan 

 group, more or less liable to affect all sorts of trees. A good example of the 

 first is Dcedalei quercina, P., never found elsewhere than on the Oak, and an 

 equally good example of the latter is Agaricus velvtijjes, Curt., which may be 

 found growing upon every sort of stump and tree. There is, indeed, a third class 

 of epixylous Fungi, the species of which are almost confined to certain trees, 

 but on rare occasions are found on various other stems. An example of this class 



