SHOUT MOTES 2G5 



Mr. Shoolbred's garden at Chepstow, but there the plant has not 

 been so much affected by the weather. — James Britten. 



A Correction. In the last line of my note (p. 236) on Spar- 

 ganium august if olium Michx., the word affine should be omitted. — 

 A. Bennett. 



REVIEWS. 



Mutations and Evolution. By R. Ruggles Gates, Ph.D., F.L.S. 

 New Pht/tologist reprint, No. 12. Win. Wesley & Son. 6s. 



In this memoir Dr. Gates takes up an eclectic attitude, while at 

 the same time emphasizing the part mutation has played in the 

 evolution of plants and animals — an emphasis only to be expected 

 from one who has published so much valuable work in support of the 

 mutation thesis. He notices the failure in universality of those 

 who would ascribe only one cause — Lamarckianism or Natural Selec- 

 tion or crossing or mutation, &c. — to the phenomenon in question, 

 holding that "many of these factors and perhaps all, may be reason- 

 ably claimed to have had some share in the evolutionary result. 1 ' 

 We have chapters on the mutation concept, on the effects on organisms 

 of the appearance of an extra chromosome, on the limitations of the 

 cell-theorv, on the recapitulation theory, and on the inheritance of 

 acquired characters, in which latter the revulsion from Weismann's 

 non-inheritance conception is supported. But the plain botanist will 

 perhaps turn with greater interest to the chapter on parallel muta- 

 tions and that on presumptive mutations in wild and cidtivated 

 plants. All these subjects are handled in a brief but capable manner, 

 every point being clearly stated and cautiously opened out, although 

 it may sometimes be difficult to agree fully with the author's conclu- 

 sions.' The possibility Dr. Gates suggests of the Aquilegia flower 

 having arisen as a peloric mutation from a zygomorphic ancestor, 

 although ingenious is scarcely convincing; for on the analogy of 

 Halenia, a genus with species having nectarial projections at the 

 base of the corolla ranging from five mere gibbosities to as many long 

 spurs, and bearing in mind the almost universal actinomorphy 

 obtaining in the Itanunculacece, the Aquilegia spurs would seem to 

 be better explained as deepenings of primitive honey-secreting nec- 

 taries brought about by simple Natural Selection, inasmuch as the 

 deeper the receptacle the more honey it would hold, and thus the 

 greater the chance of cross-pollination by insect visitors. 



There can be no two opinions as to the value of this concise and 

 well-written memoir, especially in view of the appended bibliography 

 amounting to nearly two hundred items — surely enough to satisfy 

 the most avid enquirer into the subject ! 



S. M 



