56 



GUIDE TO THE MODELS OF FUNGI. 



colour to a faint bluish-grey on being bruised, and by this character 

 it may be easily recognised. 



P. cccsius is a common fungus on dead firs, sometimes on 

 rotten stem fragments. The whole plant is ivory-white, softish-tough, 

 and stalkless. 



133. Polyporus betulinus Fr. — Pileus white, then brownish, 

 fleshy, corky, hoof-shaped, zoneless, edge obtuse, pellicle thin, 

 cracking, and sometimes separating; tubes short, minute, whitish, 

 at length separating. 



Common on living and dead trunks and branches of birch from 

 spring to early winter. This is the razor-strop fungus. Thick slices 

 of flesh cut from large examples are used as razor strops. 



The mycelium of this fungus sometimes forms sheets like hard 

 leather beneath the bark of birches, and, without producing pilei, 

 destroys the firmest wood. This leathery mycelium has been 

 described under the name of Xylostroma gigantcwn. 



GENUS XVI.—MERULIUS Fr. 



In Menilius the whole plant is at first resupinate, and the 

 hymenium is reticulated with obtuse folds, becoming gyrose and 

 imperfectly toothed, developed from a soft mucedinous substratum. 

 There are twelve British species; one only is represented by a 

 model. 1 



134. Merulius lacrymans Fr. Dry-rot. — The substance, whea 

 in fLill vigour, fleshy, moist, and pale buflf in colour, with a swoller, 



white, downy margin ; the spore-pro- 

 ducing portion, or hymenium, consists of 

 shallow, labyrinthine, gyrose, toothec 

 folds, rich orange-cinnamon in colour ; 

 when mature and in vigorous growth, 

 drops of watery fluid are exuded from 

 the hymenium. 



Dry-rot is common in buildings, par- 

 ticularly in hidden, unventilated spaces, 

 on squared wood, especially pine, but 

 spreadmg to other woods, and over plaster, 

 mortar, and other substances, where it 

 perfects itself Not common on squared 

 timber out of doors, and on fallen pines, 

 i-ij;. 43.-MeruHus lacrymans Fr. This fuugus does not grow naturally on 

 (One-third natural size.) ^^^^^ ^^^ -^ ^^ spread from pine to teak 



and destroy it. Wooden ships were in past times extensively 

 destroyed by it. During the reign of Charles II. a commission 

 was formed to inquire into the state of the navy, and Pepys, who 

 was secretary to the Admiralty, tells of thirty new ships that for 

 want ol proper care and attention had toadstools growing in their 



