THE EVOLUTION OP PLANTS 199 



REVIEW. 



The Evolution of Plants. By Dukinfield Henry Scott, M.A., 

 LL.D., F.K.S., President of the Linnean Society of London. 

 Pp. 256. Cloth, Is. net. (Home University Library.) 

 London : Williams &, Norgate. 

 This work undoubtedly furnishes a valuable contribution to 

 our knowledge of the great question summarily described under 

 the title of " Evolution." There was a period, not so very long 

 ago, when writers, those especially who undertook to popularize 

 evolutionary doctrines, professed themselves able, on an almost 

 wholly theoretical basis, to construct with confidence the entire 

 history of plants and animals as we find them at this day, to tell 

 us exactly under what form their ancestors originally appeared, 

 as well as their various transformations, and under what circum- 

 stances they have been obliged to modify themselves in order to 

 survive in the struggle for existence. This, however, is by no 

 means the method favoured by Dr. Scott. Starting with the 

 principle that, however thoroughly the doctrine of Evolution is to 

 be accepted, we can know no more concerning it than available 

 evidence tells us, he proceeds to examine the sources from wdiich 

 such evidence is to be obtained, namely, the history of cultivated 

 and domesticated species, and that preserved in the geological 

 record. The result, while of extreme interest and importance, not 

 only makes valuable additions to our knowledge on many points, 

 but likewise serves to discredit much about which many earlier 

 writers had been quite positive, and to show how dangerous it is 

 to assume that science will always be found to accord with our 

 speculations. 



To give a few examples of what appeared to many to be obvious 

 truths, which now are doubted or denied by the best authorities, 

 a beginner, says our author, might naturally suppose that such 

 plants as Duckweeds, with no regular distinction between stem 

 and leaf, represent a primitive ancestral stage in the evolution of 

 the higher families of flowering plants ; whereas all botanists are 

 agreed that they are really degenerate forms, degraded from higher 

 plants, and not primitive or ancestral at all. Again, amongst 

 Cryptogam-S, the Ferns and their allies are admittedly " higher " 

 than the Mosses (Bryophytes), wherefore most botanists have 

 believed that the former were derived if not from the latter at 

 least from plants of that type. But this view is now much shaken, 

 and it begins to appear more probable that the Higher Crypto- 

 gams are a more ancient and primitive form, and that the Bryo- 

 phytes owe their origin to reduction from some higher type. In 

 regard to a still wider class, it used to be thought, even by men of 

 high authority, that the Monocotyledons must necessarily be more 

 primitive than Dicotyledons, and accordingly appeared first ; but, 

 says Dr. Scott, it is a curious fact that none of the other fossil 

 plants have stems like Monocotyledons, while a very great num- 

 ber, like the living Gymnosperms, are of the same type with the 

 Dicotyledons. 



