SPORE-DISCHARGE IN THE TREMELLINEAE 171 



In Hirneola auricula- judae and in Auricularia mesenterica the 

 hymenium looks downwards and yet the violence of spore-dis- 

 charge is some four or five times greater than from the hymenium 

 of Stereum hirsutum and similar non-tremelloid Thelephoreae. 

 The extra violence of discharge in the two Tremellineae appears 

 to be unnecessary, but we can account for it as a primitive feature 

 derived from ancestors in which the fruit-bodies were globose or 

 lobate and the hymenium looked more or less upwards, which 

 feature has been retained through inheritance although no longer 

 of any especial use so far as spore-dispersion is concerned. 



The fruit-bodies of Calocera cornea and C. viscosa have forms 

 which are similar to those of unbranched and branched Clavariae 

 respectively. It is noteworthy, therefore, that Calocera cornea 

 and Clavaria formosa shoot off their spores with about equal 

 violence (cf. the Table, p. 169). For the sake of convenience, a 

 discussion of the relation of form to function in the fruit-bodies 

 of Calocera will be deferred until we have become acquainted with 

 this relation in Clavaria. 



In the Tremellineae, just as in the non-tremelloid Hymenomy- 

 cetes and in the Uredineae, a drop of water is excreted from the 

 hilum of each spore just before discharge takes place. This was 

 definitely observed for Hirneola auricula- judae, Exidia albida, 

 Dacryomyces deliquescens, and Calocera cornea. In all these species 

 the spores are elongated and have a curved axis, and in all of 

 them the drop excreted at the hilum is about equal in diameter to 

 the diameter of the spore (Fig. 2, p. 7). The drop begins to be 

 excreted from the hilum about 5 seconds before the discharge of 

 the spore in Exidia albida, about 10 seconds before in Hirneola 

 auricula- judae, and about 16 seconds before in Dacryomyces 

 deliquescens. The drop is always carried away by the spore when 

 the latter is shot from its sterigma. 



The Basidial and Oidial Fruit-bodies of Dacryomyces delique- 

 scens. Dacryomyces deliquescens (Fig. 59) is a very common fungus 

 in England and appears during wet weather upon the surface of 

 dead wood, such as old logs, rails, garden seats, gate-posts, etc. ; 

 but it was imperfectly described by the older systematists and by 

 Massee, and its true nature is still misunderstood by many field 



