SPORE-DISCHARGE IN THE TREMELLINEAE 159 



consists chiefly of water and, doubtless, few organisms except 

 jelly-fish have as little organic matter in them per unit of volume 

 as the more highly tremelloid Tremellineae. We may therefore 

 regard the gelatinous flesh of species of Tremella, Ulocolla, Exidia, 

 etc., so to speak, as a very cheap form of building material by the 

 use of which the fungi to a large extent sacrifice rigidity for ease 

 of construction, but by means of which the object in view, namely, 



FIG. 56. Tremella frondosa, a gelatinous fungus growing on wood and 

 having the surface of its lobes covered with the hymenium, so that 

 many of the basidia are up ward -looking. Photographed in Epping 

 Forest, Middlesex, England, by Somerville Hastings. Natural size. 



the production of a large free surface for the development of the 

 basidia and basidiospores, is successfully attained. 



Gelatinous masses are not relished as food by most animals, 

 and coverings of jelly sometimes serve to protect smaller organisms 

 from being devoured. Thus Stahl showed by experiment that a 

 fish (a species of Macropoda) and the fresh-water snail Lymnaeus 

 stagnalis will not touch frogs' eggs covered with their gelatinous 

 envelopes, but will devour these same eggs greedily as soon as 

 the envelopes have been artificially removed. 1 Stahl also showed 

 1 E. Stahl, Pflanzen und Schnecken, Jena, 1888, p. 82. 



