414 



BOTANY 



PART II 



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, .iTrrf" 



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of hyplial tissue which extends in young fructifications from tlie stalk to the 

 margin of the pileus, but is afterwards ruptured, and remains as a ring of tissue 

 encircling the stalk (Fig. 349). 



]Many of the Mushrooms found growing in the woods and fields are highly 



esteemed as articles of food. 

 Of edible species the follow- 

 ing may be named : the 

 common Field - Mushroom, 

 now extensively cultivated, 

 Psalliota campcstris (Fig. 

 349), with whitish pileus 

 and lamellae at first white, 

 then turning flesh - colour, 

 and finally becoming choco- 

 late-coloured ; Cantharcllus 

 cibarius, having an orange- 

 coloured pileus ; Lactarius 

 deliciosus, which has a red- 

 dish-yellow pileus and con- 

 tains a similarly coloured 

 milky juice in special hj'phal 

 tubes; Le'pioiajjrocer a, whose 

 white pileus is flecked with 

 brown scales; Amanita 

 caesarea with an orange pileus 

 bearing a few white scales 

 and j-ellow lamellae. The 

 brownish fructifications of 

 Armillaria mellea are also 

 edible. This species is a very 

 injurious jiarasite, especially 

 in Pine woods ; its mycelium 

 is characterised by the pro- 

 duction of photogenic sub- 

 stances which cause the 

 infected wood to appear phosphorescent in the dark {^^). The mycelium forms as 

 a resting stage blackish branched strands (rhizomori)hs) beneath the bark or 

 between the roots of the host plants. 



Of the poisonous Agaricineae the following are best known : Amanita imiscaria 

 (Fig. 350), with wliitc lamellae; Amanita hulbosa (Fig. 351), often confounded with 

 the Mushroom, with whitish or yellowish pileus and the stalk swollen at tlie base ; 

 Jlxisfiida cmetica, with a red jiileus and white lamellae ; Lactarius torminosus. 

 iiaving a shaggy, yellow or reddish-brown pileus and white milky juice. 



Jiozites go'iujylo'plwra, found in South Brazil, is of special biological interests 

 According to A. Moi.leu, this species is regularly cultivated in the nests of the 

 leaf-cutting ants. Its mycelium produces splierical swellings at the ends of the 

 hyi)hae, whicli become filled witli protoplasm, the so-called Kohl-rabi heads, and 

 serve the ants as food material. The ants prevent the development of the accessory 

 conidial fructifications peculiar to this fungus, and thus continually maintain the 

 mycelium in their nests in its vegetative condition. The fructifications, which 

 rarely occur in the nests, resemble those of Amanita muscariu, with wliich Jiozites 



Fxii. 351. — Amanita bullosa, (i nat. size.) PoJSOXOUS. 



