HISTORY OF ZOOLOGY. I 5 



sion of our knowledge was brought about. Of Swammer- 

 dam's writings attention should be called particularly to 

 " The Bible of Nature," a work to which no other of that 

 time is comparable, since it contains discoveries of great 

 accuracy on the structure of bees, May-flies, snails, etc. 

 Leemvenhoek, finally, was a most fortunate discoverer in the 

 field of microscopic research, by him introduced into 

 science. Besides other things he studied especially the tiny 

 inhabitants of the fresh waters, the "infusion-animalcu- 

 les," a more careful investigation of which has led to a 

 complete reversal of our conception of the essentials of ani- 

 mal organization. 



The Dawn of Independent Observation. The great 

 service of the above-named men consists chiefly in this, that 

 they broke away from the thraldom of book-learning and, 

 relying alone upon their own eyes and their own judgment, 

 won for man what had been quite lost, the blessing of inde- 

 pendent and unbiassed observation. They spread the 

 interest for observation of nature over a wide circle so that 

 in the eighteenth century the number of independent natural- 

 history writings had increased enormously. There were 

 busy with the study of insect structure and development, 

 de Geer in Sweden, Reaumur in France, Lyonet in Belgium, 

 Rosel von Rosenhof in Germany ; the latter besides wrote a 

 monograph on the indigenous batrachia, which is still worth 

 reading. But particularly the investigation of the infusoria 

 formed a favorite occupation for the learned and the laity, 

 as Wrisberg, von Gleichen-Russwurm, Schaffer, Eichhorn, 

 and O. F. Miiller. In most of the writings the religious- 

 character of the contemplations of nature are extraordi- 

 narily emphasized, for since we find that among these 

 writers numerous clergymen, Eichhorn in Danzig, Goeze in 

 Quedlinburg, Schaffer in Regensburg, had attained honor- 

 able positions, we have a sign that a reconciliation had 

 taken place between Christianity and natural science. As 

 a criterion of the progress made in comparison with the 

 earlier centuries, a mere glance at the illustrations is suffi- 

 cient. Any layman will at the first glance recognize the 



