200 Half-Hours with the Old Naturalists. [April, 
of Leyden, which then enjoyed a high and well-merited 
reputation as one of the first medical schools of Europe. 
How young Swammerdam had been engaged in the mean- 
time, save with the study of Entomology, is not recorded. 
Very probably the delay was in great part owing to the 
“ delicate ” health — to use an absurd modern perversion of 
language — which he never could shake off. At Leyden he 
enjoyed the instructions of Van Horne in Surgery, and of 
the then famous Sylvius de la Boe in Medicine. Here 
Swammerdam soon distinguished himself for his skill in 
anatomy, and especially in the preparation of anatomical 
specimens, in which art he opened up a new era. Here, too, 
he made the acquaintance of several important men, among 
others Steno, who was for many years his firm friend and 
admirer. Here, also, began his enmities and controversies, 
especially one with Rynier de Graaf, who claimed the merit 
of Swammerdam’s methods of making preparations, though, 
as far as it can be traced, without a particle of justice. We 
need not be surprised if the wronged discoverer replied with 
some acrimony. Indeed Swammerdam’s temper, like that 
of dyspeptics in general, was not of the sweetest ; but in 
his many controversies we find a due discrimination between 
men of merit, who may have fallen into an error, and 
charlatans, who lay claim to the researches of others and 
adulterate them with their own absurdities. Witness his 
critique on Harvey’s celebrated treatise “ De Generatione,” 
and his denunciation of Gcedart, whom he accuses of defiling 
the views of Harvey. 
About 1665 we find him visiting several parts of France 
for the benefit of his health. He lived for some time at 
Saumur, and it is said at Lyon. Here he had the advantage 
of studying a fauna differing in many respeCts from that of 
Holland, and here he continuedjris entomological researches. 
In particular he studied various species of dragonflies and 
the Ephemeridse. Here he began that treatise on Ephemera 
Swammerdamiana, as now named, which Prof. Westwood 
justly pronounces admirable. Whilst at Saumur he seems 
also to have discovered the valves of the lymphatics. 
Thence he repaired to Paris, and in company with his 
friend Steno, resided for some time at the house of Thevenot, 
at Issy, chiefly engaged with dissecting inseCts. Here he 
was introduced to the Senator Van Bemmingen, at that 
time Dutch Ambassador at the French Court. 
Returning to Holland he was chiefly engaged with the 
study of Human Anatomy and of Medicine, and became 
the leading spirit of a medical society founded at Amsterdam. 
