BOOK REVIEWS 185
rendered students of aboriginal American culture a distinct service in showing that there is much confusion in the accounts of the early writers, that a wide diffusion of certain plant names seems to have occurred during the century after the Discovery, and that African influence may have been something of a factor in it all. That, however, the plants themselves were of foreign origin and were unknown in America until introduced in the early sixteenth century, he has, in the reviewer's opinion, quite failed to prove. It is clear that there is a problem here which demands a scientific and scholarly study, but this the volume under discussion cannot be said to supply.
R. B. DIXON
Vertebrate Zoology. HORATIO HACKETT NEWMAN, Professor of Zoology and Embryology in the University of Chicago. The MacMillan Company: New York, 1920. Pp. xiii + 432, 217 figs. A textbook of vertebrate zoology or comparative anatomy is neces- sarily largely a compilation. Its value is determined by the author's choice of material and authorities as well as his presentation of the sub- ject. Professor Newman has been successful in a wise selection of material from the best books on this subject. The greater part of the data is derived from such authorities as Brehm, Cope, Flower, Lydekker, Gadow, Gegenbauer, Gregory, Haswell, Hertwig, Huxley, Jordan, Keibel, Kingsley, Lillie, Lull, Mall, Mathew, Minot, Osborn, Parker, Patten, Scott, Weber, Wiedersheim, Wilder, and Williston. This list is sufficient to show that the book contains well-balanced proportions of embryology, paleontology, comparative anatomy, and phylogeny. The first three subjects are used to good advantage in establishing phylogenetic relation- ships and tiresome details that do not serve this end are omitted.
A feature of the book is the introduction and application of Child's axial gradient conception in the interpretation of vertebrate structures. There are three axes of the vertebrate body: a primary antero-posterior axis, a secondary dorso- ventral axis, and a tertiary bilateral axis. The generalization is that the organs of highest dynamic activity are at the apical ends and those of least dynamic activity are at the basal ends of these axes.
The book is adequately illustrated with 217 text-figures. Although not one of these figures is original, the author's contribution here has been an important one. He has regrouped and combined figures from other authors to very good advantage.
Four pages are devoted to man. They are totally inadequate and
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