INTRODUCTION TO CRYPTOQAMIC BOTANY. 3G3 



by any striking characters ; for though, as is usual, many of the 

 finer species, such as P. xanthopus and so,ce7', belong to the 

 tropics, they have their fair share of uninteresting forms. P. 

 sacer, indeed, is a most striking object, and is regarded with 

 veneration by the negroes of the West African coast. Boletus 

 is very much confined to more temperate regions, while typical 

 HexagonicB affect only the tropical. The bright scarlet of 

 P. sanguineus has its representative in the warmer parts of 

 Europe, in P. cinnabarrinus, a species which, however, ex- 

 tends also to the tropics. The size which is attained by some 

 of these productions is enormous. Even in Great Britain, P. 

 fraxineus is sometimes a yard across, and some of the softer 

 species form masses large enough to fill a common cart.* 



397. Boletus edulis is much esteemed as a delicate article 

 of food, and some of the Polypori are esculent, but their close 

 texture makes them, for the most part, very indigestible. 

 Several species of Polyporus are used for tinder or moxa, 

 while others form excellent razor-strops. Polyporus offi^cinalis 

 is a well-known purgative, the use of which is, however, now 

 superseded by better remedies. Many of the species are very 

 destructive to trunks of trees. It is true that in the first 

 instance they grow on parts which are diseased, but their 

 mycelium spreads with great rapidity, and the moment any 

 gi'owth of this kind appears the tree should be felled, or, if 

 the tree is important as ornamental timber, the affected parts 

 should be carefully removed, and a strong solution of sulphate 

 of copper or corrosive sublimate be applied. A few of the 

 species, moreover, are extremely destructive to wooden fabrics, 

 the only remedy against which is perfect ventilation, winter 



* I have given, in Lindley's Vegetable Kingdom, the result of close 

 examination, comparative lists of Fungi in Java, Cuba, and the Philip- 

 pine Islands, and something of the same kind in Hooker's Flora of 

 New Zealand, It will be seen from these, how prominent a part the 

 Polypori bear in the lists of exotic Fungi, where the climate is hot or 

 equable; how local many of the species are, and how widely distributed 

 others. It will be seen, too, how many European sjiecies are found in 

 such localities. The details have been omitted here, in consequence of the 

 mass of matter before me, which requires to be compressed into as 

 small a space as possible. 



