REVIEWS 171 



costly character of the work will place it beyond the reach of that large majority of 

 students for whom the algas are but one of many groups which claim their atten- 

 tion and interest. E. J. Salisbury. 



Principles of Plant Teratology. Vols. I and II, By W. C. Worsdell, 

 F.L.S. [Vol. I, pp. xxiv + 270, with 25 plates and 60 text-figures ; Vol. II, 

 pp. xvi + 296, with 25 plates and 95 text-figures.] (London : Ray Society, 

 191 5 and 1916. Price 25s. net per volume.) 



After the lapse of nearly half a century since the appearance of Masters's volume, 

 botanists are again laid under a debt to the Ray Society for the publication of a 

 work on vegetable abnormalities. No one is better fitted to deal with the large 

 number of facts that have accumulated since Masters's day than the author of the 

 present volumes, who brings to the task many original observations of his own 

 gathered from a wide field. 



The first volume deals with the vegetative organs of flowering plants and the 

 comparatively few recorded abnormalities in the Fungi and Bryophyta, and the 

 second with the flower. The author, in his Introduction, states that he regards 

 teratological investigation as the most important method for the elucidation of 

 morphological problems — a view with which many of us will hardly be in agree- 

 ment. As Mr. Worsdell himself admits, all abnormalities are not reversions ; 

 some are progressive, others purely pathological phenomena. In this decision 

 as to the significance of any given case, we can only rely on the indications 

 afforded us by Comparative Morphology and Ontogeny. Herein lies the difficulty 

 of teratological interpretation, and hence the significance attached to any 

 abnormality will often vary with the interpreter. 



Although we cannot always agree with Mr. Worsdell's conclusions, the pre- 

 sentation of which is perhaps at times too forensic, in nearly all cases the explanations 

 advanced have the great merit of stimulating thought. 



Many of the views expressed deal with controversial matters, but space does 

 not permit of our discussing these in detail. However, we must enter a protest 

 against the statement (Vol. II, p. 128) to the effect that "the facts of floral 

 morphology in the Ranunculaceas strongly support the view of the staminal origin 

 of the calyx. All the facts put forward by the author in support of this hypo- 

 thesis are capable of quite another interpretation, and the position taken up really 

 rests on the d priori ground that positive dedoublement of the perianth is most 

 unlikely to have occurred. As a matter of fact, such numerical increase without 

 metamorphosis, does take place quite commonly in several genera belonging to 

 this family. 



The work is profusely illustrated with text-figures and photographs, and one 

 can only regret that several of the latter, owing to lack of gradation and faulty 

 lighting, scarcely do justice to the beauty of the subjects. A very commendable 

 feature is the excellent index which accompanies each of the volumes and greatly 

 adds to their usefulness. E. J. Salisbury. 



Plants, Seeds, and Currents in the West Indies and Azores. By H. B. Guppy, 

 M.B., F.R.S.E. [Pp. vi + 531, with three maps and frontispiece.] (London : 

 Williams & Norgate, 1917. Price 25s. net.) 



It is with a sense of pleasurable anticipation that the reader opens a new work on 

 seed dispersal by Mr. Guppy. One cannot, however, attempt to do more than 

 adumbrate the contents of a book so replete with facts and interesting suggestions. 



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