374 



BOTANY 



Fig. 300. — Crucibulum vul~ 

 gave. Longitudinal section 

 of a closed fructification. 

 ( x circa 3, from v. Tavel's 

 Fungi.) 



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structure. They are nearly spherical, usually about 5 cm. thick, and have, a thick, 



light brown, leathery peridium which finally becomes cracked and ruptured at the 

 apex. The gleba is black when ripe, and contains 

 numerous chambers filled with interwoven hyphae which 

 produce lateral, pear-shaped basidia with four sessile 

 spores (Fig. 299, 2). This species, which is considered 

 poisonous, is sometimes mis- 

 taken for one of the Truffle 

 Fungi. 



The genera Boiyista and 

 Lycoperdon (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 Bovisia may even become half a metre in 



diameter. The peridium is formed of two layers ; the 



outer disappears at maturity, while the inner dehisces at 



the summit. The hymenial layer of basidia, in the Fungi 



of this group, line the chambers of the gleba. The 



chambers are also provided with a fibrous eapillitium con- 

 sisting of brown, thick -walled, branched hyphae which 



spring from the walls, and in ripe fructifications, fill the 



whole internal cavity with a brown, fibrous, felted mass 



containing the spores. The fibres correspond biologically 



to the capillitia of Myxomycetes, although different mor- 

 phologically. The fructifications are edible while still 



young and white, and have an agreeable taste, but when 



ripe they are dry, and were formerly used for stopping 



the flow of blood. 



In the related genus Geaster (Earth-star) the peridia 



of the nearly spherical fructifications 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 fructifications of Crucibulum and of other related 



genera have an altogether different structure. They 



develop on rotten wood or on the ground as small white 



or brown, cup-shaped bodies (Fig. 300), containing a 



number of stalked or sessile, thick- walled peridiola. The 



peridiola are produced by the differentiation of the internal 



tissue of the gleba, unused portions of which become dis- 

 solved. They are lenticular in shape, and enclose an 



inner cavity lined with the hymcnium. The fructifica- 

 tions are at first closed ; when ruptured, the peridium 



forms a crucible-shaped receptacle containing the peridiola. 

 The highest development of the fructifications is 



exhibited by the PJiattoideae, of which Phallus impudicus 



(Stink-horn) is a well-known example. This Fungus is usually regarded as poisonous, 





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Fig. 301. — Phallus impudicus. 

 (After Krombholz, i nat. 

 size.) 



