352 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



880. They vary greatly both in form and substance. At first 

 sight but little relation could be imagined between the thin 

 outspread Corticium, and the noble stipitate Amanita, with 

 its stem, volva, and ring ; and yet no relation can be more 

 undoubted if the resupinate form, consisting of nothing but 

 mycelium and fruit, be traced up through all its multiplied 

 gradations. Nor is the difference less as regards the hyme- 

 nium, which in the one case is perfectly uniform, and in the 

 other most beautifully and regularly plicate. In point of sub- 

 stance, we have forms as delicate and floccose as the most 

 tender mould ; while others are fleshy, gelatinous, corky, or 

 even as hard as wood, and part assume the aspect of car- 

 tilage, whereas others are hard and resinous. 



381. This order affords the most usefid of the tribe, and at 

 the same time the most dangerous. Agaricus presents a 

 multitude of esculent species, some of which form no imma- 

 terial part of the food of countries in which they abound ; but 

 their use requires the exercise of much caution and discrimi- 

 nation, as the most virulent poisons are to be found in 

 species closely related to those which are esculent. Hymeno- 

 mycetes occur in all parts of the world, even in the warmest, 

 and at the same time they ascend almost to the extreme 

 limits of vegetation. They abound, however, most in temperate 

 countries, especially in those where the hygrometer ranges 

 high. Mere rain is not sufficient for their development, except 

 the atmosphere is usually moist. The richest plot in the world, 

 perhaps, for Hymenomycetes is afforded by parts of Sweden, 

 where individuals are no less multitudinous than species. 

 Indeed, no one can have a notion of the variety of forms, who 

 has not had the opportunity of j^artaking of the treasures of 

 that garden of mycology. By the kindness of Professor Fries 

 I am in possession of authentic specimens of a very large pro- 

 portion of the species he has described ; and the perfect dis- 

 tinctness of the greater part, as well as the beauty, is most 

 striking. Parts of America alone, which produces many of the 

 most curious and rare European forms, vie with it in interest ; 

 and I have happily been in a condition to compare the myco- 

 logy of both countries, from the possession of a large portion 



