J. D. Thrasher, one on RNA synthesis and one on protein synthesis, are noteworthy because 

 of the discussion of differentiating systems such as the erythroid system and the lens. The 

 second of these chapters moreover has a brief section on the control of cell division and 

 differentiation. Finally, a chapter by H. C. Slavkin deals with the dynamics of the interactions 

 between extracellular and cell-surface proteins, and particularly with the role of such 

 interactions in the control of morphogenesis and differentiation in a variety of organs. The 

 other chapters deal with DNA, lipids, carbohydrates, and calcification. 

 The book is well produced and illustrated, and the subject index is very detailed. 



Monographs 



39 



REGENERATION: key to understanding normal and abnormal growth and development. 1970. 



By S. M. ROSE 



Appleton-Century-Crofts, Meredith Corporation, New York. 276 pp., 45 figs., combined author, 



taxonomic, and subject index. $ 8.80 



Contents: I. Genetic theory of cellular differentiation; II. Spatial tissue relationships in 

 the control of lens regeneration in the eyes of salamanders; III Polarized control of regener- 

 ation in the amphibian limb; IV. The transport of messages controlling growth and differen- 

 tiation in plants; V. Protozoa — polarized control of differentiation within the cortex of 

 single cells; VI. Regeneration in worms — neural control of polarized gradients of differenti- 

 ation; VII. Regeneration in coelenterates; VIII. The origin and operation of polarized control 

 in embryos; IX. Tumor formation — a case of never-completed regeneration 



This book is written in the form of a series of essays. The connecting thread is the author's 

 theory of polarized inhibitory control as a mechanism for pattern formation. This was first 

 formulated about 20 years ago; although, as a generalization, it has recently been criticized 

 from various quarters (cf. Wolpert, J. Theoret. Biol. 25, 1969), it has been fruitful in more 

 limited areas; and it certainly was a novel and interesting idea to bring together in one book 

 discussions of regeneration in unicellular and multicellular animals, plant morphogenesis, 

 embryogenesis, and tumour formation against a common theoretical background. 



The present reviewer has two major objections against the book, however. One is that the 

 evidence is often selected so as to fit the favoured hypothesis, leaving other evidence unmen- 

 tioned. The other objection mainly concerns the first chapter, in which evidence from the 

 molecular biology of prokaryotes is naively extrapolated to higher organisms, totally 

 disregarding the complexities of gene regulation in the latter. The specific inhibitors found in 

 some developing higher organisms are simply equated with the gene repressors of bacteria. 

 For these and other reasons the book is definitely not suited for students who still have 

 insufficient background in this general area. 



Some very important recent and older evidence is not included. To mention but a few 

 examples: the treatment of blastemal autonomy and of the role of the epidermis in limb 

 regeneration is incomplete; the treatment of disto-proximal regional organization in the 

 embryonic limb is superficial — a more complete and objective analysis would show that there 

 is also proximo-distal control in the limb. The dual hypothesis of neural induction (Nieuw- 

 koop, Toivonen), and the evidence for it, goes unmentioned. An area that is completely lacking 

 is the regeneration of insect limbs and the development of insect segmental epidermis — it 

 would be very difficult to fit the insect data into the theory of polarized inhibitory control. Also, 

 one would have wished for a more explicit consideration of the relationships between polarity, 

 gradients, and cellular differentiation, and for a more formal treatment of the author's own 

 hypothesis, which is still couched in rather imprecise terms. 



Nevertheless, many parts of the book make interesting reading, provided the reader uses his 

 critical faculties. The author is at his best when describing older work that seems almost for- 

 gotten, yet provides a great deal of interesting information. This reviewer found the discussion 

 of bio-electrical phenomena in relation to morphological patterns particularly interesting. 



The book is beautifully produced and very well illustrated. The index is very detailed. 



340 



