3 o8 FUNGI 



worthy, and the physiological substitution for the latter of fatty matters 

 Glycogen is found in the asci of Uiscomycetes and Tuberacese, and in the 

 vegetative cells of these and other fungi. Crystalloids of albuminoid 

 substance occur in the sporophores of Mucorini. Nuclei are of frequent 

 occurrence in the cells of the reproductive system of many fungi, and in 

 the vegetative cells of the Saprolegniese and other groups, though abso- 

 lutely satisfactory evidence has not been produced with regard to their 

 common presence in the thallus of fungi, apart from the reproductive 

 system. Unsegmented hyphae resemble the Siphoneous Algas in their 

 multinucleate condition, though single cells of segmented hyphae also 

 sometimes contain several. 



Cell-membrane. The typical cell-membranes of fungi consist of a 

 substance differing from cellulose in its behaviour to the usual reagents, 

 which is therefore known by the special name of Fungus-cellulose. Richter 

 contends that this difference is more apparent than real, since he found 

 that after prolonged maceration in a 7-8 per cent, potash solution, mem- 

 branes exhibited the ordinary cellulose reaction which had refused the 

 reaction after treatment of the usual kind with boiling potash solution, 

 &c. De Bary, who originally gave the name of Fungus-cellulose to the 

 membranes of fungi, welcomes these observations as confirming the un- 

 doubted near affinity of such membranes to ordinary cellulose, but 

 points out that it merely proves that the membranes of the fungi 

 operated on by Richter are altered by maceration with potash in the 

 way described. ' Whether this alteration consists in the removal of 

 some substance which was present from the first must remain uncertain ; 

 such an explanation has not been proved, and others are at least pos- 

 sible ' (* Comp. Morph.,' p. 13). It is specially noteworthy that the 

 membranes of certain filamentous fungi (Saprolegnieae, &c.) exhibit the 

 ordinary blue reaction with iodine. 



The membranes of fungi undergo thickening and stratification, but 

 are rarely pitted. The capillitium-threads of Lycoperdon are pitted, for 

 example, and spiral and annular thickening occurs in the corresponding 

 structure in Batarrea. Membranes very frequently become coloured 

 with age, and undergo sclerosis ; while in contrast to that condition 

 other membranes often occur, which, though hard and horny in a dry 

 state, swell up enormously by absorption of water, and acquire a gela- 

 tinous consistency. 



Calcium oxalate, though of common occurrence in various forms 

 in fungi, is of extreme rarity within their cells ; Russula adusta (Fr.) and 

 Mutinus caninus (Fr.) are the only recorded instances known to us. 



