Recently published Ornithological Works. 201 



suggested as likely to bring about the changes in animals 

 and plants that have undoubtedly occurred. 



The authors divide the Evolutionists of to-day into 

 three schools, which they terra the Neo-Lamarckian, the 

 Wallacei an, and the Neo-Darwinian. Of these the first, 

 represented by Cope, Spencer, Cunningham, Haeckel, and 

 Naegcli, do not believe that Natural Selection is the im- 

 portant factor in the Evolutionary process, and that acquired 

 characters can be and often are inherited. The Wallaceiaus, 

 represented by Weisraann, Poulton, and apparently by 

 Lankester, believe in the all-sufficiency of Natural Selection 

 to explain everything, and deny that acquired characters can 

 ever be inherited. The third school, the Neo-Darwiniaus, 

 to which the authors claim to belong, and in which they 

 include Bateson, De Vries, Kellogg, and T. H. Morgan, 

 steer a middle course, and, though still laying stress on the 

 great importance of Natural Selection, believe that there 

 are many other factors of importance to be taken into 

 consideration. 



The book is illustrated by a number of uncoloured plates 

 to shew examples of phenomena among birds, such as 

 recognition-marks, mimicry, and sexual and seasonal di- 

 morphism. There is not much novelty in it, but it is worth 

 reading by those who are interested in the subject, as 

 containing a ma^s of information on the question of the 

 origin of species brought together from different quarters. 

 Birds are specially alluded to in the chapters on " Mu- 

 tatiou " and " Hybridism." 



9. Dresser on Palaarctic Birds' Eggs, 



[Eggs of the Birds of Europe, including- all the Species inhabiting the 

 'Western Pahearctic Area. By II. E. Dresser. Pts. XIX.-XX. Sep- 

 tember, 1909.] 



Mr. Dresser is now fast approaching the termination of 

 his labours, though he finds that two more parts will be 

 necessary to complete this work, owing to an unexpected 

 accumulation of material during its progress, and more 

 particularly to new discoveries in Northern Asia. Several 



