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it as a purely mechanical organ, which bores through the over- 
lying tissues, preparatory to the subsequent growth of the 
paraphyses of the developing apothecium. 
Darbishire 7 , in his recent work on Physcici pulverulenta , 
rejects Lindau’s view for that Lichen, mainly upon the 
grounds of the unsuitable structural character of the tricho- 
gyne as a boring organ, and of the relative positions of 
the organic apex of the young apothecium and the line of 
growth of the trichogyne. These, he points out, are most 
frequently in quite different vertical planes, and therefore 
the trichogyne cannot prepare the way for the growth of the 
paraphyses, which he regards as the true boring or dissolving 
organs. Whilst on the one hand this objection of the relative 
position of trichogyne and perithecium will not hold in 
Poronia , on the other hand it seems impossible to relegate 
to the organ any function as an ‘organ of conception,’ for, 
in the first place, no trace of spermogonia with spermatia has 
been found in this Fungus, and in the second place, the only 
other form of spore which occurs besides the ascospores is 
that of the conidia which precede the ascospores, and which 
germinate readily, producing a cycle of development quite 
indistinguishable from that resulting from the germination 
of an ascospore. Hence, if the trichogyne-like process in 
Poronia is rightly regarded as the homologue of the similar 
organ occurring in the Florideae and the Collemaceae—and 
this seems the only tenable view—we may, so far as concerns 
its relation to a fertilization-process, regard it as a degenerate 
organ, reminding us of the functionless fertilization-tubes 
formed by the antheridia of some species of the Saprolegnieae. 
It would then be quite intelligible, if, having lost this sexual 
function, the organ should become more mechanical in its 
action. Undoubtedly (as Darbishire contends for Pkyscia 
pulverulenta :) in Poronia the chief part of the work of boring 
through or dissolving the overlying hyphae is performed by 
the hyphae forming the lateral wall and the periphyses, but 
1 See Darbishire, Ueber die Apothecienentwickelung der Flechte Physcia pulve- 
mlenta. Pringsh. Jahrb. xxxiv, Heft 2. 
