278 PROCEE'DINGS OF SOCIETUiS. 



such a general habit iu leguminous and composite plants is familiar 

 to every one. What have been hitherto spoken of as jnimetic plants 

 are simply cnses where a plant belonging to one family puts on the 

 habit characteristic of another. This is entirely different from mimicry 

 among animals, inasmuch as the resembling plants are hardly ever found 

 with those they resemble, but more usually in widely different regions. 

 Mutisia speciosa, from Western South America, a Composite, has a scan- 

 dent leguminous habit, and closely agrees in its foliage with Lntliyras 

 marltimiis of the European shores (although that plant is not strictly 

 speaking scandrnt). In the same way three different genera of Ferns have 

 species (found in distant parts of the world) indistinguishable in a barren 

 state. The term Mimicry seems objectionable in these cases, and I pro- 

 pose Pseudomoi'i^hism as a substitute. As to the cause of the pheno- 

 menon, I can only suggest that the influence of similar external circum- 

 stances moulds plants into the similar form most advantageous to them. 

 An illustration is aft'orded by the closely resembling bud scales which are 

 found in widely separated Natural Orders of deciduous ti'ces as modifica- 

 tions of stipules. I do not, however, think that the moulding influence 

 need always be the same. I believe that diflerent external conditions 

 may produce the same result ; in this respect they may be called analogous. 

 For example, several identical plants are found on the seashore, and also 

 on mountains. The reason is, I believe, that they are equally able to tole- 

 rate the effect of soda salts and also of mountain climate; the tolerance of 

 either unfavourable condition gives them the advantaii,e over less elastici- 

 cally constituted plants, and the two are therefore analogous in their effect, 



Professor Dickson remarked that instances of so-called mimicry were 



by no means uncommon amongst plants. Comparing Eitphorbiacere with 

 CactncerB and Stapdia, it was often practically impossible to distinguisii 

 them without seeing their flowers. In these cases similar physical condi- 

 tions appear to have produced the similarity. Mr. Carruthers said that 



though not wholly agreeing with the views of Professor Thiselton Dyer, 

 some facts occurred to his mind which rather sustained those views. The 

 vegetation which bordered fresh- water streams throughout the world all 

 conformed, more or less, in certain characteristics of foliage to the willow 

 type ; this was true even of Australian Myrtaceous plants. With regard 

 to Mutisia, he might say that he believed that from tiie suborder of 

 which it was the type alone, the habit of alnr.ost all the principal Orders of 

 flowering plants might be represented. He fully bore out the statements 

 as to Ferns, and he pointed out that the wliole subject constituted one of 



the special difficulties of fossil botany. Professor Balfour could confirm 



the remarks of the last speaker as to the important bearing of this sub- 

 ject upon fossil botany. The speculations as to the effect of maritime 

 conditions upon plants were particularly interesting. It was by no means 

 easy to give a satisfactory explanation of the occurrence of strand plants 

 upon mountains. Plantago muritiiiia might be added to those already 

 mentioned. Anneria maritima did not occur at the highest elevations. 

 He had induced Professor Voelcker to analyse the ashes of this plant 

 from its most inland situation in Scotland, ^q.\\ ]\IacDhui. They con- 

 tained less soda and more potash than strand plants, and no iodine, 



Avhich was present in the latter. Professor E. P. Wright admitted the 



importance of the distinction which had been laid down. He supposed, 

 however, that it would not be contended that such a thing as true 



