A MANUAL OF ELEMEXTAET BOTANY FOR INDIA 115 



dealt with bv Professor Oliver ; but here again the change in our 

 methods is marked. The single type and the floral schedule have 

 given place to several types and fuller structural detail under each 

 Order, though the classification according to Bentham and Hooker 

 remains. It is somewhat remarkable that a professor in an agri- 

 cultural college studiously omits the least mention of any economic 

 uses of the plants of which he writes. A brief chapter on ecology, a 

 carefully drawn up glossary, and a Latin index of the plants men- 

 tioned, with their Tamil and Telugu names, concludes the work. We 

 hope that in the next edition the Urdu names may at least be added, 

 so that tlie use of so excellent a manual in Northern India may be 

 facilitated. 



Among minor matters we notice that the author evidently uses the 

 term " saccate " in a different sense from that usual with us, since he 

 terms the distinctly calcarate flower of Eulophia " slightly saccate " ; 

 and, in the face of all recent work on the seeds of Orcliidaceae^ his 

 statement that all Monocotyledons are endospermic is assuredly too 

 sweeping. 



The 356 text-figures have all been specially drawn for the work, 

 and this well-printed well-bound volume is produced for three shillings ! 

 Certainly cheap labour is not exclusively Chinese ! 



G. S. BOULGEE. 



Critical Researches on the Potamogetons. By J. O. Hagstrom. 

 4to. Pp. 2S1, 119 figures in text. Stocldiolm : Almquist & 

 Wiksells. 1916. 



This work (reprinted from Kungl. Svenska Vetensk. Handl. 

 Band 55, No. 5) is the most important that has been published on 

 the genus, and is the result of many years labour. In the intro- 

 ductory part the author tells how he proceeded with his work, 

 combining anatomical, biological and morphological characters. It 

 may be doubted whether too great reliance has not been placed on the 

 first of these. One regrets to see that Dr. Hagstrom considers that 

 the results of cultivation are not as valuable as most of us think. 

 He writes : " The hybrids must be studied according as Nature pro- 

 duces them. Cultivation and experiments in hybridization may not 

 lead to great results as to the solution of this intricate question." 

 To this I must demur : having seen the results of the late Alfred 

 Fryer's work in this direction, I consider cultivation is a very great 

 help — anyhow it aftords a negative to some of the proposed hybrids 

 given. With regard to the anatomical characters, the late C. B. 

 Clarke once showed me at Kew the result of too great reliance on 

 these : I think it was in the Gutti^ercB, where the author of the 

 monograph, relying on this, made two species of one plant. 



Dr. Hagstrom's work contains thirty-seven new species, some 

 twenty-one new hybrids, many varieties, and very many new forms. 

 Of the species, two at least are founded on single specimens, without 

 date or collector's name; even their origin is uncertain. To found 

 Australian species on single specimens is certainly unwise : no country 

 supplies more debatable species. No doubt some species might safely 



