SEVENTEENTH AND EIGHTEENTH CENTURIES 131 

 Rene Antoine Ferchault de Reaumur was born of noble and wealthy 

 parents in the year 1683. He received his education at a Jesuit college, after- 

 wards studying jurisprudence in Paris, but he soon abandoned that career and 

 applied himself whole-heartedly to natural science. Having inherited a for- 

 tune, he was able to lead the life of a private scholar; membership in the 

 French Academy of Science was the only distinction he obtained. He died in 



1757- 



Reaumur was active in many branches of natural science, both theoreti- 

 cal and applied. He invented improved methods of iron-refining and made 

 important contributions to our knowledge of the expansion of gases and 

 fluids and of specific heat. He is best known for his invention of the eighty- 

 degree thermometer scale, which bears his name and which is still used in 

 many countries. In biology, too, his activities have been many-sided and 

 important. His greatest and most famous work is his Memoires pour servir a 

 rhistoire des insectes, a work in six large quarto volumes. This work is un- 

 doubtedly of fundamental importance in insect biology and is in fact one of 

 the most monumental works written in this field of research. It offers a 

 number of extremely valuable contributions to the knowledge of the anatomi- 

 cal structure of the insects, their evolutional history and conditions of life. 

 His chief master is Swammerdam, whose system he in the main adopts, but 

 he considerably widens the sphere of the latter's researches. True, he did 

 not possess the master's incomparable ability in the work of preparing mater- 

 ial, but instead he had at his disposal a greater wealth of material for his 

 researches, while a long life made it possible for him to carry out lengthy 

 and laborious series of observations and experiments on the living habits of 

 insects. The community life of the social insects, in particular of the bees, 

 the development of the parasitic Hymenoptera, and the activities of leaf- 

 mining and gall-forming in ects may be specially mentioned among the sub- 

 jects dealt with by Reaumur in his great work — subjects to which he made 

 important contributions. Besides these his book contains a mass of valuable 

 detailed descriptions of larval and imaginal forms from practically all in- 

 sect groups. 



Reaumur's physiological researches 

 Moreover, outside the sphere of insects he has presented biology with the 

 results of important discoveries. Thus, he has established the fact that the 

 shell of molluscs is formed by means of a secretive process, and in connexion 

 therewith he studied the formation of pearls in mussels. He studied also the 

 movements of a number of primitive animal forms, he investigated the elec- 

 tric phenomena in the ray, and he further observed the regeneration of the 

 extremities and other parts of the body of crayfish, in regard to this latter 

 phenomenon producing a theory reminiscent of Buffon's hypothesis as to the 

 body's being composed of organized particles. And, finally, he carried out 



