INTRODUCTION OF THE MICROSCOPE 73 



took, he likewise overdid this, and yielded himself to a sort 

 of fanatical worship until the end of his life, in 1680. Had 

 he possessed a more vigorous constitution he would have 

 been greater as a man. He lived, in all, but forty-three years; 

 the last six or seven years were unproductive because of his 

 mental distractions, and before that, much of his time had 

 been lost through sickness. 



The Biblia Naturae. — It is time to ask, What, with all his 

 talents and prodigious application, did he leave to science? 

 This is best answered by an examination of the Biblia Na- 

 turce, under which title all his work was collected. His treatise 

 on Bees and Mayflies and a few other articles were pub- 

 lished during his lifetime, but a large part of his observations 

 remained entirely unknown until they were published in this 

 book fifty-seven years after his death. In the folio edition 

 (1737-1738) it embraces 410 pages of text and fifty-three 

 plates, replete with figures of original observations. It "con- 

 tains about a dozen life-histories of insects worked out in more 

 or less detail. Of these, the mayfly is the most famous, that on 

 the honey-bee the most elaborate." The greater amount of 

 his work was in structural entomology. It is known that he 

 had a collection of about three thousand different species of 

 insects, which for that period was a very large one. There 

 is, however, a considerable amount of work on other animals; 

 the fine anatomy of the snail, the structure of the clam, the 

 squid; observations on the structure and development of the 

 frog; observations on the contraction of the muscles, etc., etc. 



It is to be remembered that Swammerdam was extremely 

 exact in all that he did. His descriptions are models of 

 accuracy and completeness. 



Fig. 16 shows reduced sketches of his illustrations of the 

 structure of the snail. The upper sketch shows the central 

 nervous system and the nerve trunks connected therewith, 

 and the lower figure shows the shell and the principal muscles. 



