SEVENTEENTH AND EIGHTEENTH CENTURIES 167 

 On the whole, Holland during the latter half of the seventeenth century 

 proved a centre of biological research. Of the many prominent scientists who 

 lived and worked in that country during that period it is possible to mention 

 only a few of the most important — those who in one way or another led 

 research into fresh directions. 



Jan Swammerdam was born in Amsterdam in the year 1637. His father 

 was an apothecary who by saving had accumulated a considerable fortune 

 and was, moreover, interested in natural science. He possessed a natural col- 

 lection, which he augmented and looked after with great care. He had in- 

 tended his son to take orders, but as the study of nature seemed to be his 

 sole interest, he was permitted to study to become a doctor. After preliminary 

 studies in his native town he entered the University of Ley den in 1661. Even 

 then he had already proved a clever technician in the anatomical sphere, 

 and he rapidly acquired fame for his splendid dissecting and injection-work. 

 He formed a lifelong friendship with Steno, who was about the same age 

 and who happened to be visiting Leyden at the time; they worked together 

 and travelled together to Paris in order to continue their studies there. Here 

 Swammerdam found a new friend in the person of the King's librarian, The- 

 venot, a friend who throughout his life loyally assisted him in every possible 

 way. Returning to his native country, Swammerdam graduated at Leyden in 

 1667 with a dissertation on respiration and then settled down at his father's 

 place in Amsterdam. He had already earlier applied himself to the study of 

 the anatomy of the lower animals, and this interest now engaged all his 

 powers. During the short years that remained to him he achieved results 

 which not only left all his predecessors far behind, but actually remained 

 unexcelled for the space of more than a hundred years. In the mean while 

 his fortunes took an extremely unhappy turn. He contracted a malarial fever, 

 which, except for occasional intervals, never left him for the rest of his life. 

 At the same time the strain entailed on him by his work impaired his health. 

 Besides, he was of a passionate nature; his writings are full of bitter con- 

 troversy, and his quarrels about questions of scientific priority brought him 

 many enemies. On the other hand, he had several loyal friends, who stood 

 by him to the end. Worst of all, however, he fell out with his own family; 

 his father, who seems to have been an economical and surly old man, thought 

 that it was about time that his son, whom he had supported for more than 

 thirty years, applied himself to medical practice or some other profession 

 that might provide him with an income. In preparation for this, young 

 Swammerdam was sent into the country to recover his frail health, but he 

 spent night and day engrossed in his investigations, so that his health went 

 from bad to worse. After repeated quarrels his father finally deprived him 

 of all financial support. Swammerdam found himself in dire need and sought 

 in vain to sell his collections in order to buy his daily bread. Even his intel- 



