SEVENTEENTH AND EIGHTEENTH CENTURIES x6} 

 of hitherto unknown higher animals, dealing with their anatomy, mor- 

 phology, and habits. Among his biological works, however, the place of 

 honour is held by his work on New Mammal Species from the Kodentia. In 

 this work he gives an account, with a thoroughness that was quite unprec- 

 edented, of the new rodents discovered by him in Russia and Siberia; in 

 it he endeavours to present not merely diagnoses as resulting from his ex- 

 aminations, such as his age was usually content with, but a true general 

 knowledge of the animals described, based on a close study of their exterior, 

 with careful measurements of every part of their body, thorough anatomical 

 investigations and illustrations, and detailed descriptions of the conditions 

 under which the animals lived. The anatomical section is particularly useful 

 and constitutes the best work so far carried out in the investigation of the 

 inner structure of the members of an entire order of animals. Though direct 

 points of comparison do not occur very often in the work, nevertheless the 

 descriptions are so detailed and at the same time so comprehensive that the 

 whole must be regarded as one of the really sound pieces of work that have 

 paved the way for modern comparative anatomy. 



At this point we may close our account of the biology of the eighteenth 

 century. Before, however, proceeding to the cultural phenomena — already 

 hinted at above — that represent the basis of the natural science of the 

 nineteenth century, we must take a glance at a radical reform in another 

 sphere of natural science, which contributed towards the creation of modern 

 biology. 



