727 



flora in each ; just as tadpoles, after passing their transition state, 

 creep out of their canal or river on the opposite baaks, and thus give 

 to the fields or meadows on the right hand a supply of frogs, of the 

 same appearance and size as those poured out upon the fields and 

 meadows of the left." — p. 219. 



Mr. Miller here quotes from the ' Vestiges ' a passage wherein the 

 author of that work, after citing several several striking examples of a 

 correspondence of form in the floras of neighbouring lands, propounds 

 his own hypothesis of " a spread of terrestrial vegetation from the 

 sea into the lands adjacent" as a much " simpler cause " of such 

 correspondence than Professor Forbes's surmise " that the spaces 

 now occupied by the intermediate seas must have been dry land at 

 the time when these floras were created ;" and asserts as a fact, ad- 

 mitting of no dispute, that " the community of forms in the various 

 regions opposed to each other merely indicates a distinct marine crea- 

 tion in each of the oceanic areas respectively interposed, and which 

 would naturally advance into the lands nearest to it, as far as circum- 

 stances of soil and climate were found agreeable." One obvious coh- 

 sequence of a belief in this simpler mode of distribution would be the 

 necessity of holding, contrary to all experience, that dulse and hen- 

 ware* became, through a very wonderful metamorphosis, cabbage 

 and spinach ; that kelp-weed and tangle bourgeoned into oaks and 

 willows ; and that slack, rope-weed, green rawf shot up into mangel- 

 wurzel, rye-glass and clover ! " Well may we exclaim with our 

 author, " Simple, certainly !" — especially as the time allowed by the 

 author of the 'Vestiges' for the operation of all these marvellous 

 transmutations, whereby " fucoids and confervas became dicotyle- 

 donous and monocotyledonous plants," was so brief that not a single 

 whorl in the shell of Purpura lapillus or of Turritella terebra was al- 

 tered during that period, nor did the slightest change occur in the mi- 

 nute projections of the hinges of Cyprina Islandica or Astarte borea- 

 lis, or in any of the nicer peculiarities of their muscular impressions. 



From the chapter on the evidence afforded by the Silarian mol- 

 luscs and the fossil flora, we quote a passage relating to the contem- 

 poraneous existence of some of the higher forms of vegetation with 

 those of a far lower class, during the carboniferous period of the 

 earth's history, and the true bearing of this now well ascertained fact 

 upon the development hypothesis, into the service of which has 



* Rhodymenia palmata and Alavia esculenta. 



f Porphyra laciniata, Chorda filuua, and Enteromorpha corapressa. 



