468 



BOTANY 



PART II 





in an inner mass of tissue termed the GLEBA ; it contains numerous chambers, 

 which are either filled with loosely-interwoven hyphae with lateral branches 

 terminating in basidia, or their walls are lined with a basidial hymenium. 



The Gasteromycetes are saprophytes, and develop their mycelium in the humus 

 soil of woods and meadows. Their fructifications, 

 like those of the Hymenomycetes, are raised above 

 the surface of the substratum, except in the group 

 of the Hymenogastreae, which possesses subter- 

 ranean, tuberous fructifications resembling those of 

 the Tuberaceae. 



The fructifications of Scleroderina vulgare (Fig. 

 420, 1) have a comparatively simple structure. 

 They are nearly spherical, usually about 5 cm. 

 thick, and have a thick, light brown, leathery 

 peridium which finally becomes cracked and rup- 

 tured at the apex. The gleba is black when ripe, 

 and contains numerous chambers filled witli inter- 

 woven hyphae which produce pear-shaped basidia 

 with four sessile spores (Fig. 420, 2). This species, 

 which is considered poisonous, is sometimes mistaken 

 for one of the Truffle Fungi. 



The genera Bovista and Lycoperdon (Fig. 420, 3) 

 (Puff balls) have also spherical fructifications, which 

 are at first white and later of a brown colour. In 

 the last-named genus they are also stalked, and in 

 the case of Lycoperdon Bovista may even become half 

 a metre in diameter. The peridium is formed of two 

 layers ; the outer separates at maturity, while the 

 inner dehisces at the summit. The hymenial layer 

 of basidia, in the fungi of this group, lines the 

 chambers of the gleba. The chambers are also pro- 

 vided with a fibrous capillitium consisting of 

 brown, thick- walled, branched hyphae which spring 

 from the walls, and aid in distributing the spores. 

 The fructifications are edible while still young and 

 white. When mature they contain urea. 



In the related genus Geaster (Earth-star) (Fig. 

 420, 4) the peridia of the nearly spherical fructifica- 

 tions are also composed of two envelopes. When 

 the dry fruit dehisces, the outer envelope splits into several stellate segments, 

 and the inner layer of the peridium becomes perforated by an apical opening. 



The highest development of the fructifications is exhibited by the Phalloideae( 86 ), 

 of which Ithyphallus impudicus (Stink-horn) is a well-known exam pie. -This fungus 

 is usually regarded as poisonous. It was formerly employed in a salve as a 

 remedy for gout. Its fructification recalls that of the discomycetous Morchella, 

 but it has quite a different manner of development. A fructification of this 

 species of Phallus is about 15 cm. high. It has a thick, hollow stalk of a white 

 colour and perforated with pores or chambers. Surmounting the stalk is a bell- 

 shaped pileus covered with a brownish-green gleba which, when ripe, is converted 

 into a slimy mass (Fig. 421). When young the fructification forms a white, egg- 

 shaped body, and is wholly enveloped by a double-walled peridium with an inter- 



FIG. 421. lihyphallus impudicus. 

 ( nat. size.) 



