230 NATURAL SCIENCE [April 



tion. It is not surprising, considering the growth of science, that 

 it has been found necessary to add 8500 titles since the first 

 edition published in 1885. Another publication, which should be 

 found useful to others than those for whom it is primarily intended, 

 is the " International Exchange List " of the Smithsonian Institu- 

 tion, being a list of 9414 learned societies, museums, universities, 

 and other bodies with which American publications are exchanged. 



