366 INTRODUCTION TO CETPTOGAMIO BOTANY. 



Nyctalis is always parasitic on decaying Lactarii, and there 

 are one or two Agarics, of which the most important is A. 

 Lovei, with a similar habit. 



402. As regards sculpture or vestment, they exhibit various 

 pecuHarities, especially in the latter respect, from the smoothest 

 highly polished surface, like that of ivory, to the shaggy scales 

 of A. squarrosus. Many of the lower genera contain but 

 very few species, but almost all the more important divisions 

 abound in species. Lentinus and Marasmius are the glory of 

 tropical mycology, though both have numerous representatives, 

 especially the latter in European woods. Cortinarius, which 

 is scarcely represented in the tropics, has its centre in Sweden, 

 where it abounds both in species and individuals. A strag- 

 gling species occurs in Australia, and two or three amongst 

 the mountains north of Calcutta, and a few in North America; 

 and though England has many species, the quantity is not to 

 be compared with what occur in Sweden. Schizophyllum, is 

 a species of warmer climates, and in them almost universal. 

 It is a rare inhabitant of England, and for the most part im- 

 ported. Goiyrinus, as the name implies, is a native of hot- 

 beds and other exuberant soil. The growth is extremely 

 rapid, insomuch that some species are capable of exhibiting 

 every phase of growth and of decay in a few hours. They are 

 the Ephemerides of vegetables. A species has been developed 

 more than once in the course of a few hours, on the dressings 

 applied to amputated limbs. The notion that they luxuriate, 

 especially in tropical climes, has not at present been confirmed. 

 Of all the genera, however, Agaricus is the most prolific. 

 After all the eliminations which have been made, there remain 

 at least a thousand truly distinct species; and when it is con- 

 sidered how little the tropical kinds have been studied, it is 

 certain that many additions will yet be made to the genus. 

 Notwithstanding the notion that these productions are the 

 growth of the fortuitous concurrence of certain elements, it is 

 allowed by those who have studied the genus well, that in the 

 whole vegetable kingdom there are no more decidedly distinct 

 species than in Agaricus. The species of tropical climates 

 are in general of little beauty ; but in the lofty mountains of 



