Book Reviews 465

cium gates are in dire need of propping up with better factual evidence.

In some of the systems studied, such as the nema- todes (by Ward) or insects (pheromones by Kramer and other chemoreceptors by Hansen), knowledge of the molecular mechanism of the sensory process is still rudimentary. In systems in which the receptors are sensitive to the binding of individual molecules or where whole ranges of types of molecules give re- sponses, the problems the investigator faces are im- mense and compensated only by a closer similarity of such systems to higher and intrinsically more impor- tant systems in ourselves.

The problem of responses given to disparate types of molecules has led Wilkinson, in his fascinating chapter on chemotaxis in leukocytes, to postulate that, rather than highly stereo-specific receptors, leu- kocytes possess receptors which recognize generally amphipathic molecules containing a hydrophobic moi- ety together with polar sites that may be negatively charged. Such a general recognition ability may suit the specialized needs of the leukocyte in its role as a scavenger seeking out denatured proteins or lipids released from damaged cells.

More specific receptors, however, are required by most other types of cell, and such specificity is no- where better illustrated than in the sexual chemotactic responses of molds and plants which are ably re- viewed by Mascarenhas. Although many of the mole- cules that such systems use to trigger the induction of sexual organs in approaching sexual hyphae are very unusual and complex, they have sufficiently enticed the interest of organic chemists that many of them have had their structures chemically elucidated. The peculiarity of the chemical compounds involved and the “ping-pang” type of sequential induction between male and female hyphae of the water mold Achlya give ample cause for wonder at the fascinating com- plexity of “simple” systems, but must make workers in much less amenable “complex” systems shudder at the thought of the complexity they may have yet to find.

Overall I found this an exciting book-not quite one to be read at a sitting, but exciting enough to compel one to read through to the end with occasional lapses for thought about the implications that these systems might have on one’s own particular branch of science. Sensory systems are so important to the working of all living things that a peek at the way a bacterium senses danger or an insect sniffs its mate is indeed worth the ocular sensory input required.

Peter C. Newell Department of Biochemistry University of Oxford Oxford OX1 3QU, England

Perspectives on Development

An Introduction to Developmental Biology, by D. Ede. New York: John Wiley (Halsted). 246 pp. $17.50.

Developmental Biology: Embryos, Plants and Re- generation, by J. W. Brookbank. New York: Harper 8 Row. 451 pp. $17.95.

Biology of Developing Systems, by P. Grant. New York: Holt, Rinehart & Winston. 736 pp. $19.95.

Because of its relevance not only to embryogenesis but to malignancy, regeneration, metamorphosis and even aging, developmental biology is enjoying a re- surgence in the laboratory and in the lecture hall. Research with developmental systems has defined new paradigms in gene structure and control, in the biochemistry of morphogenesis, in the mechanisms of cell shape changes, in the nature of totipotency and in the acquisition and stability of the differentiated state. To deal with these advances, today’s college student of developmental biology must be fluent in cell biology, biochemistry and genetics. In the past year, the three texts listed above have appeared and have been aimed at the advanced undergraduate or beginning graduate student. In scope and depth, only Philip Grant’s book comes close to doing justice to the exceedingly dynamic discipline of developmental biology. In Developmental Biology: Embryos, Plants and Regeneration, John W. Brookbank takes an in- teresting systems approach in which the development of the echinoderms, annelids and molluscs, frogs, amniotes, Drosophila and plants are covered sequen- tially. The book is necessarily somewhat repetitive and stresses the differences between developing sys- tems. Much of what is new and excellent in develop- mental biology is omitted. The slim volume by Ede falls far short of satisfying even minimal requirements for a developmental text. Except for the author’s own interest-pattern formation in the limb-the book might have been written a decade ago. In the realms of differentiation and molecular development the cov- erage is often in error or misleading. To make matters worse, the writing is cumbersome, unclear and sorely in need of extensive editing.

The book by Philip Grant has previously been ana- lyzed in detail by this reviewer (Quart. Rev. Biol., January 1979); suffice it to say here that the text covers all the important aspects of developmental biology except the evolutionary. Its strong points are its breadth and thoughtfulness, its illustrations and its excellent handling of embryology’s more historical experiments. Weaknesses include an occasional fail-