TITE LTCITEN SYMlJrOSlS 2G7 



environment. There is no means of conceiving the origin of even 

 a filament of mycelium, except as originating in aqueous environment, 

 and the sea is the original watery solution holding the food-supplies. 

 Even a filamentous soma must have a long marine ancestry behind it. 

 If Lichens present the form-factors, filamentous growth, not to 

 mention reproductive phases and a life-cycle, still characteristic of 

 sea-weeds, the presumption is that they inherit this somatic equip- 

 ment directly from marine algie ; and such features of equipment are 

 retained (though more or less open to deterioration) since they have 

 proved useful, in the long run, or at iiny rate not injurious, under new 

 subayrial conditions. The adult lichen-thallus is now a heterotrophic 

 fungus-soma to which intrusive algai have been added, and is not to be 

 judged by early stages of 'synthetic ' development, merely because it 

 can no longer exist without its algal helots ; any more, apparently, 

 than can many orchids without their attendant mycorhiza— and 

 the 'consortium' is a pi-turesque myth. 



Lichens thus present an interesting case of an algal race, deterio- 

 rating along the lines of a heterotrophic existence, yet arrested, as it 

 were, on the somatic down-grade, by the adoption of intrusive algal 

 units of lower degree to suhserve photosynthesis (much in the manner 

 of the marine worm Convolnfa). Thus arrested, they have been 

 .enabled to retain more definite expression of more deeply inherent 

 factors of sea-weed habit and construction than any other race of 

 Fungi ; though closely paralleled b}^ such types as Xylaria (Asco- 

 mycete) and Clavaria (Basldiomycete), which have followed the full 

 fungus-progression as holosaprophytic on decaying plant-residues. 



There can be little doubt that such a view will enlarge one's con- 

 ception, not only of the remarkable history of these often despised 

 fungus-races, as compared on one hand with the surviving Florideje of 

 the sea, and on the other with the great range of Ascomycetous 

 phyla ; but also it must throw light on the general problems of the 

 changes of biological environment, which may have been effective 

 in such a striking response, as included within what has been termed 

 the period of the subaerial transmigration. 



ALABASTRA DIVERSA.— Part XXXIII*. 

 Br SpENCEii Le M. Moore, B.Sc, F.L.S. 



(Continued from p. 226.) 



3. Miscellanea Afrtcaxa (conf.). 



Asclepiadacej3. 



Batesanthus intriisus, sp. nov. Planta glabra, caule volubili 

 distanter folioso uti inflorescentia saltern in sicco fusco-purpureo ; 

 foliis amplis petiolatis ovato-cordatis breviter acuminatis a23ice acutis 

 utrobique palllde nitidis pap3a*aceis ; paniculis axillaribus pedun- 

 culatis foliis circlter sequllongls laxe plurifloris ; 'pedicellis minute 

 bracteatis quam flores longioribus ; calycis segmentis parvulls del- 



* Types in the National Herbarium. 



