The Postural Development of Infant Chimpanzees

names are frequently expanded or contracted in their coverage as knowledge and understanding increase. The defining of genera and species is a relatively orderly and legitimate business, but even here internecine controversy may rage.7 How much more difficult is the extra-legal status of the higher taxonomic categories which seem subject to polemics rather than arbitration! An item that lies more deeply than the question of names also arises in relation to the Aschelminthes, namely, the concept of a phylum. For the assemblage of forms here included certainly is a less compact integral unit than most other phyla. In fact, many zoologists will be tempted to brand such a category, which inter alia bonds rotifers, gastrotrichs, and nematodes into one phylum, as a wastebasket. The author was well aware of this likelihood but, nevertheless, like Jenny, she did make up her mind. A large and important part of 7'he Invertebrates is its illustrations which fortunately are numerous and informative. One might wish for more technical polish in their execution, but as a whole they do make their points effectively. More serious is the complete failure to show any scale on the drawings. The author may retort that anyone with common sense knows that a whole animal is bigger than its egg and that an organ is somewhere in between. But this hardly seems enough when everything from a sperm to a habit sketch may be assembled in a single plate. Furthermore, in figures taken from other sources one needs to know whether they are used directly, redrawn, or otherwise modified. This is not indicated. Figures almost never are used to illustrate any points except those dealing with anatomy, histology, and embryology. The nearly complete neglect of graphic illustration in presenting data of life cycles, distribution, physiology, and behavior give the books a superficially old-fashioned look, an appearance , as indicated above, not in accord with the broad scope of textual coverage. From what has been said it is obvious that The Invertebrates is an indispensable work for all zoologists. An even broader usefulness is indicated for the two new volumes here reviewed since many animals of great medical, parasitological, and economic importance are included in the phyla covered. Biological scientists in general owe a debt of gratitude to Miss Hyman for her sound and stimulating scholarship. Her further progress in completing the whole work will be awaited with great expectation. This …