150 



HUTCHINSON'S POPULAR BOTANY 



rich in these fairy lamps, most of which belong to the same great genus, 

 Agaricus, though the prevailing colour of their light is white. One species, 

 found by Drummond in the valley of the Swan River, deserves particular 

 mention, if only on account of its size and weight. It measured sixteen 

 inches in diameter and a foot in height, and weighed about five pounds. 

 Even these statements, however, are eclipsed by the account of the Spruce 

 log which the Rev. M. J. Berkeley saw, and which was literally ablaze on 

 the inside with the white plasmodium of some unidentified species of Myxo- 

 gaster* When some of the luminous matter was " wrapped in five folds of 



paper, the light penetrated through 

 all the folds on either side as brightly 

 as if the specimen was exposed," albeit 

 the luminosity had been already going 

 on for three days ! 



M. Tulasne, who made some careful 

 experiments in vegetable phosphor- 

 escence, found that the light from 

 luminous Fungi was extinguished in 

 vacuo or non-respirable gases, and 

 from this he inferred that " it is due 

 to a slow combustion without heat, 

 arising from a chemical combination 

 of the oxygen of the atmosphere, in- 

 haled by the Fungus, with a substance 

 peculiar to the plant." 



Whether this is the true explana- 

 tion of the phenomenon, we do not 

 pretend to say, and those who may 

 desire to pursue their inquiries on the 

 subject will do well to consult the 

 learned paper by M. Tulasne in Ann. 

 des Sci. Nat. (1848), or Dr. Phipson's 

 little book on Phosphorescence, in which 



much curious information has been brought together. Neverthe- 

 less, we think it has been pretty clearly demonstrated that luminosity 

 in the lower plants is connected almost exclusively with one or other 

 of those two important functions, assimilation and respiration the former 

 in the case of cave-growing Mosses and deep-sea Algce ; the latter in 

 the case of certain Fungi which lodge their spores in decaying wood ; 

 whereas the luminosity which has been observed in the higher plants, 

 and which appears to be confined to white, yellow, orange, and scarlet 



* The Myxogasters appear as small incrustations on dead leaves and twigs, and vary in 

 colour from black to bright orange. They form an anomalous group of Fungi, or as some say 

 of Protozoa, low forms of animal life. 



FIG. 187. MISTLETOE (Viscum album). 



Leaves, buds and fruit are here shown. A photograph 



of a larger portion of the plant will be found on page 



36 (fig. 59). 



