gene activation are not discussed separately, but of course appear in several 

 chapters because they are inseparable components of whole-plant physiology. 

 The only chapter in which they are discussed at length is that on photo- 

 morphogenesis by H. Mohr. 



The book is produced in very good offset print. It is illustrated with line 

 drawings but has no photographs. Each chapter has its own extensive 

 bibliography, very conveniently subdivided into selected further reading and 

 papers cited in the text. The book is concluded by a detailed subject index. 



344 



