12 A PLAIN AND EASY ACCOUNT 



dried edible fungi sent to the International Exhibition 

 of 1862, but also in the Himalayas and in the Rocky 

 Mountains, as well as in Terra del Fuego, New Zealand, 

 and Australia, to say nothing of European countries, 

 certain species afford wholesome and nutritious food. 

 Of their chemical composition we are very deficient in 

 information. Few authentically-determined species have 

 yet come under the cognizance of the chemist, and there 

 is but little doubt that not only does the composition 

 vary greatly in different species, as evidenced by their 

 wholesome or unwholesome properties, but also in the 

 same species under different conditions of climate and 

 habitat, as well as during the different stages of its 

 existence ; a few hours being sufficient in some cases 

 to convert a wholesome food into a very injurious and, 

 perhaps, dangerous substance. 



GILL-BEARING FUNGI. 



WITH a view to a more complete knowledge of the 

 structure and arrangement of Fungi, it will be advisable 

 to commence with an examination of one of the best 

 known, as a type of the higher divisions of this inter- 

 esting group of plants. Every one knows what a mush- 

 room is, at least so far as regards its external appearance. 

 If we carefully remove the soil from the base of the 

 stem which bears the cap-like receptacle of mushrooms, 

 we shall lay bare a number of pale entangled threads, 

 which constitute the mycelium or spawn. These 



