JOHN SWAMMERDAM. 125 



ing the importance of the task designed for him, 

 he judged himself incapable of discharging the du- 

 ties of a religious instructor. On representing the 

 matter to his parents, he received their permission to 

 commence the study of medicine. Being frequently 

 employed in cleaning and arranging his father's ca- 

 binet^ he gradually acquired a liking to natural 

 history, and even at an early age began to form a 

 collection of insects, which he disposed into classes, 

 agreeably to ideas derived from observation and the 

 descriptions of authors. Day and night he pursued 

 his favourite employment, searching the woods and 

 fields, the sandhills and muddy shores, the lakes, 

 rivers, and canals, for insects, worms, and moUusca, 

 until he acquired, even while a youth, a more exten- 

 sive and more accurate knowledge of the lower ani- 

 mals than all the naturalists who had preceded him. 



In 1661, he went to Leyden, for the purpose of 

 attending the lectures at the celebrated university 

 of that city. There he remained two years, study- 

 ing surgery with Van Home, and medicine with 

 Franciscus Sylvius de le Boe, with as much dili- 

 gence as he had previously displayed in his other 

 pursuits. During the whole of this time he enjoyed 

 the friendship of Steno and De Graaf ; and, becom- 

 ing much attached to the study of anatomy, he 

 exerted his utmost ingenuity in devising means for 

 effectually preserving his preparations. 



He then went to Paris to improve himself in his pro- 

 fession. Therelie continued theexamination of insects, 

 and had the good fortune to discover the valves in the 

 lymphatic vessels. After this he resided for some 

 time at Lyons, where he lived on terms of intimacy 

 with Thevenot the celebrated traveller^ who intro- 



