their inclusion in later editions should be considered. 



The information in part II is biological rather than physiol- 

 ogical, but there is much of interest there for embryologists : 

 gestation and incubation times, modes of fertilization and de- 

 velopment, breeding seasons, etc. (for both vertebrates and 

 invertebrates ) . 



Two new appendixes have been added: a listing of scientific 

 names with corresponding common names, and the converse. The 

 classification outline for living animals and plants has been 

 considerably modified for several phyla. 



Vols. II and III will appear in 1973 and 197^, respectively. 

 The books are produced with great care and are extensively 

 indexed. 



244 



