gO SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 48 
cluded all the animals the brains of which were weighed, irrespec- 
tive of the age of the animal or the condition of its body. In the 
second class, which is naturally much reduced in number, only those 
animals are included which were full grown and in which the state 
of the nutrition of the body was fair; and here the groups have been 
arranged on the basis of the average brain-body relation only. 
The data reveal a number of points which incite comment, but 
this may better be postponed until the series can be sufficiently in- 
creased. 
To facilitate reference I append a brief bibliography, limited to the 
principal contributions to the subject of brain weight in animals; 
in the works cited are mentioned a number of minor contributions. 
The numbers preceding the names of the animals are the catalogue 
numbers of the brains preserved in the Division of Physical Anthro- 
pology in the U. S. National Museum. 
