Apeii. 17, 190S] 



SCIENCE 



619 



vegetable kingdom long before it becomes 

 obvious morphologically. 



In the final chapter, which is entitled " Re- 

 sults, Phyletic and Morphological," some of 

 the conclusions may be quoted, as " Both 

 Mosses and Liverworts may with probability 

 be held to be blind branches of descent, which 

 illustrate nevertheless phyletic progressions 

 that illuminate the origin of sterile tissues 

 from those potentially fertile, and the estab- 

 lishment of a self-nourishing system in the 

 sporophyte." " The phyletic relationship of 

 the Sphenophyllales and Equisetales has un- 

 doubtedly been a very close one; the distin- 

 guishing features are not to be found in the 

 primary plan or construction of the shoot, so 

 much as in the secondary modifications of 

 number and relation of the appendages, and 

 of their branching, together with changes in 

 the originally protostelic structure of the axis. 

 Such considerations support the conclusion 

 that the Sporangiophoric Pteridophytes con- 

 stitute a brush of naturally related phyletic 

 lines." " The Filicales appear as the most 

 divergent phylum of homosporous Pterido- 

 phytes." Speaking of the vegetative system 

 of the sporophyte in higher plants the author 

 says : " Taking an evolutionary course of its 

 own it diverged more and more in character 

 from the propagative system. The final result 

 is seen in the Angiosperms which are now 

 dominant: here the flowers differ widely from 

 the vegetative shoots, though the plan of each 

 resembles that of the primitive shoot from 

 which both sprang. But whatever the modern 

 complications may be, comparison along lines 

 which have been pursued in this volume indi- 

 cates that the sporophyte, which is the essen- 

 tial feature in the flora of the land, is refer- 

 able back in its origin to post-sexual compli- 

 cations: it appears to have originated as a 

 phase interpolated between the events of chro- 

 mosome-doubling and chromosome-reduction 

 in the primitive life-cycle of plants ■„! aquatic 

 habit." 



It merely remains to say that the publishers 

 have brought out the book in a style befitting 

 its importance — paper, type, presswork and 

 illustrations, all being good and pleasing to 

 the eye. The illustrations, of which there are 



361, are plain, and while no attempt has been 

 made to secm-e artistic effect, they do what 

 they were intended to accomplish — namely, 

 they help to explain the subject-matter. It is 

 in all ways a thoroughly satisfactory book. 

 Charles E. Bessey 

 The University of Nebraska 



Monographie des Onychophores. By E. L. 

 BouviEE. Extracted from Annales de Sci- 

 ences Naturelles, Zoologie (1907), pp. 383 



+ 318, Pis. xni. 



The splendid monograph of the Proto- 

 tracheata recently published by Professor 

 Bouvier of the Paris Museum deserves a 

 rather extended notice, because of the great 

 interest attaching to the group of which it 

 treats, and the fact that the work, owing to 

 its place of publication, is very little known 

 to American naturalists. A most interesting 

 preface is headed by an appropriate motto, 

 taken from Albert Gaudry: "Vieux habitants 

 de la terre, apprenez-nous d' ou vous etes 

 venus." A section follows, containing a gen- 

 eral account of the morphology of the animals, 

 with no less than 44 new and admirable text- 

 figures. The bulk of the book is, of course, 

 occupied with the detailed descriptions of 

 the genera and species, while at the end are 

 a complete bibliography and a check list. 

 Everything is worked out in the most complete 

 manner possible, and the history of each 

 species is fully narrated; in its careful atten- 

 tion to detail and arrangement, the mono- 

 graph may be classed with Scudder's great 

 work on the butterflies of New England and 

 Taylor's " Monograph of the British Land and 

 Freshwater Mollusca." 



The history of the classification of the 

 Prototracheata is interesting. Up to 1894, all 

 the known species were referred to the genus 

 Peripatus, but in that year Pocoek, in spite of 

 opposition, recognized three genera, two pro- 

 posed by him as new. This was thought revo- 

 lutionary at the time; but to-day Professor 

 Bouvier describes two families and seven 

 genera, with excellent characters! The num- 

 ber of species has been increased from a mere 

 handful to fifty, nineteen of them described by 

 Professor Bouvier. The gi'oup remains as 



