THE DESCENDING SAP 



149 



are now 

 known to 

 be simply 

 the my- 

 celi a of 

 various 

 species of 

 Agari c, 

 the large 

 fungi to 

 which our 

 c o mmon 

 edible 

 Mushroom 

 b el ongs. 

 A small 

 portion of 

 one of 

 these rhiz- 

 omorphs, 

 with the 

 mushroom 

 which is 

 its fruit, 

 or spore- 

 bearing body (sporophore), is shown in figs. 181 and 183. The phosphores- 

 cence of the rhizomorph is said to be due to slow decay and oxidation, 

 either in the mycelia or fructification of the Fungi; and Sir Joseph 

 Hooker found that alcohol, heat, and dryness soon dissipate it. That 

 eminent botanist frequently saw the luminous mycelia in the dead wood 

 used for fuel by the natives of Northern India, and has furnished 

 some remarks on the subject in his interesting and informing Himalayan 

 Journals. 



Ayaricus olearius, a Fungus common in the South of France, is also 

 highly luminous. It grows in the dark crevices of the Olive-stems in 

 November and December, when the gills under the pileus or cap are said to 

 shine as brightly as a glow-worm. It has been proved to emit light only 

 when alive. Under experiment it has been found to cease to do so at once 

 when deprived of oxygen. Equally remarkable is the Brazilian . species of 

 phosphorescent Agaricus (A. gardneri) a parasite on the Pintado Palm 

 the light of which is of a pale greenish hue, and equals in brilliancy that of 

 the larger fire-flies ; while Borneo can boast a closely allied species, also 

 parasitical on trees, the greenish luminous glow of which has been likened 

 to the glow of the electric discharge. Australia appears to be exceptionally 



FIG. 186 A MYXOGASTER. 



One of these little-known but wonderful organisms (Brejeldia maxima) is here shown in the plasmodium 

 tage, when it has the appearance and consistency of cream. At a later stage it gathers into cushion- 



" ion the ] " 



with a purple-brown crust, under whi< 



plasmodium breaks up into dust-like spores. 



