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 term the Neo-Lamarckian, the 
Wallaceian, and the Neo-Darwinian. Of these the first, 
represented by Cope, Spencer, Cunningham, Haeckel, and 
Naegeli, 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 Wallaceians, 
represented by Weismann, 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-Darwinians, 
to which the authors claim to belong, and in which they 
include Bateson, De Vries, Kellogg, and T. II. 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 mass 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¬ 
tation ” and “ Hybridism.” 
9. Dresser on Palaarctic Birds’ Eggs. 
[Eggs of the Birds of Europe, including all the Species inhabiting the 
Western Palsearctic Area. By H. 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 
