SPORE-DISCHARGE IN THE TREMELLINEAE 157 



branches, logs, and tree stumps. However, there are many non- 

 tremelloid hymenomycetous fruit-bodies, e.g. those of Stereum, 

 Lenzites, Schizophyllum, and Polystictus, which are also lignicolous 

 and which appear to be particularly well adapted to that mode 

 of existence. Thus there are two types of lignicolous fruit-bodies 

 the tremelloid and the non-tremelloid. 



In dry weather, dead sticks, branches, etc., dry up rather 

 rapidly. As if to meet and overcome this disadvantage, the 

 tremelloid and npn-tremelloid lignicolous fruit-bodies are so con- 

 structed that, during drought, they dry up without losing their 

 vitality, and that, upon the advent of rain, they rapidly absorb 

 water, revive, and resume their one dominant function of pro- 

 ducing and liberating spores. The re-absorption of water by 

 dried fruit-bodies takes place by one of two physical means : (1) 

 capillarity and (2) imbibition, the first being characteristic of 

 non-tremelloid fruit-bodies, e.g. those of Stereum, Lenzites, 

 Schizophyllum, and Polystictus, and the second characteristic 

 of tremelloid fruit-bodies, e.g. Hirneola, Auricularia, Exidia, 

 Dacryomyces, and Calocera. 



In non-tremelloid lignicolous fruit-bodies which revive in wet 

 weather after drought there are numerous, large, interconnected 

 air-spaces between the hyphae of the pileus-flesh ; and free water, 

 falling on the pileus, is sucked into these spaces by capillarity. 

 Thus a dried fruit-body of Lenzites betulina or Polystictus hirsutus, 

 when rain comes, rapidly absorbs and stores free water in its 

 capillary system. On the other hand, as already pointed out, 

 tremelloid fruit-bodies all of which are lignicolous and revive 

 in wet weather after drought possess no such interhyphal air- 

 spaces as those just described and therefore cannot absorb water 

 by capillarity. However, the flesh of tremelloid fruit-bodies is 

 composed of a continuous gelatinous matrix in which the living 

 hyphae are embedded. This gelatinous matrix takes the place 

 of a capillary system in the absorption of water, the water being 

 absorbed by imbibition instead of capillarity. When free water 

 comes in contact with a dried gelatinous fruit-body, e.g. of Exidia 

 albida or Dacryomyces deliquescens, the fruit-body rapidly imbibes 

 water at its surface and the water so imbibed is drawn by imbibition 



