bo THE JOURNAL OF BOTANY 



Vortrdge fiber Botayiische Stammesgeschichte — Ein Lehrbuch der 

 Pflanzenstjstematih. Von J. P. Lotsy. Bd. iii. — Cormo- 

 phyta Siphonogamia, Erster Teil. 8vo, pp. 1055, tt. 661. 

 Jena : Fischer. 1911. Price 30 mark. 



With the completion of this volume Dr. Lotsy approaches the 

 end of his great work on the special morphology and classification 

 of the great plant groups. One-third of the present ponderous 

 volume is devoted to Gymnosperms, the remainder to a portion 

 of the Angiosperms. The book is profusely illustrated ; but after 

 allowing for the space occupied by the figures there remains 

 sufficient subject-matter to render the volume one which will 

 demand the very serious consideration of the student, and which 

 will provide the teacher with much matter for reflection. 



Dr. Lotsy, with the indefatigable energy which he has shown 

 throughout this important work, has not only brought together 

 facts, but has also considered the various theories on the origin 

 and relationships of the different groups and their divisions. And 

 having considered these, Dr. Lotsy does not hesitate to give his 

 own opinion on the matter in question and arrange his subjects 

 accordingly. Hence, while it is improbable that his system will 

 meet with general acceptance — there is a vast deal to be done, for 

 instance, before we can fully understand the relationships of the 

 constituent divisions of the Angiosperms — Dr. Lotsy's work must 

 demand consideration as a capable attempt to solve some of the 

 problems involved in these relationships. 



It is impossible in the scope of a short review to do justice 

 to the mass of facts and suggestions which Dr. Lotsy has brought 

 together, but some idea of the nature and arrangement of the 

 subject-matter may be given. 



First, as regards the Gymnosperms, to which eleven lectures 

 are devoted. They are studied under two heads — Conifers and 

 Gnetales. The Conifers are divided into two groups — Florales 

 and Inflorescentiales ; the former includes the Podocar2nnece, 

 AraucarinecB, and CupressinecB, in which, in the author's opinion, 

 the female "cone" represents a flower; the latter includes the 

 TaxinecB, TaxodinecB, and Abietinece, in which the female cone 

 represents an inflorescence. The position of Taxinece in the 

 second group is explained by Cephalotaxus, which is regarded as 

 a connecting-link. Between the two groups " there appears to 

 be no direct relationship," at any rate their common origin lies 

 very far back. For while there is every reason to derive the 

 Inflorescentiales from the Cycad group, the origin of the Florales 

 is obscure. The author suggests that they have sprung from the 

 vascular cryptogams before the differentiation of the great Cycad 

 group, which has given rise to the younger division, the Inflore- 

 scentiales. Gnetales are exhaustively considered, and Pearson's 

 suggestion of their division into Ephedroidecd (Ephedra) and 

 GnetoidecR {Gnetum and Wehoitschiaj is adopted. The author 

 concludes that the group represents the end of a developmental- 

 series, and therefore the Angiosperms cannot be derived from it. 



In his arrangement of the Angiosperms Dr. Lotsy has been 



