198 THE MINUTE ANATOMISTS 



Swammerdam found in the lung, are the parasites now 

 called Rhabdonema. 



Here too we find Swammerdam's account of his 

 discovery of the red blood-corpuscles of the frog. 

 Foster's translation^ follows: — -"In the blood I per- 

 ceived the serum in which floated an immense number 

 of rounded particles, possessing the shape of as it were 

 a flat oval, but nevertheless wholly regular. These par- 

 ticles seemed however to contain within themselves the 

 humour of other particles [or rather, another humour 

 besides — the nucleus ?]. When they were looked at 

 sideways, they resembled transparent rods, as it were, 

 and many other figures, according no doubt to the 

 different ways in which they were rolled about in the 

 serum of the blood. I remarked besides that the colour 

 of the objects was the paler the more highly they were 

 magnified by means of the microscope." ^ 



The chapter ends with a discussion of muscular con- 

 traction, which can be studied in the frog with peculiar 

 advantage, partly because the nerves and muscles are 

 so readily exposed and separated, partly because the 

 power of contraction, as in all cold-blooded animals, 

 persists long after removal from the body. Swam- 



1 History of Physiology, p. 99. B. N., p. 835. 



* The wrong date of 1658 is assigned to Swammerdam's discovery of the red 

 blood-corpuscles of the frog by Foster (loc. cit.), by Darmstadter, and probably 

 by other writers. In 1658 Swammerdam had not begun his regular anatomical 

 studies ; he went to Leyden for this purpose in 1661. No date is assigned, so 

 far as I know, either in the Biblia Naturce or in Boerhaave's Life prefixed 

 thereto, to the discovery of the red corpuscles, but on p. 839 of the Biblia 

 Naturce the wrong date of 1658 is given to Swammerdam's demonstration of a 

 muscle nerve preparation before Cosmo III, Duke of Tuscany ; it is well- 

 known that the Duke's visit took place in 1668. Swammerdam's observations 

 on the red corpuscles of the frog cannot therefore, it would seem, be dated at 

 all. In B. iVC , p{). 69, 70 he speaks of human blood as having been examined 

 by him, and found to contain reddish corpuscles floating in a clear liquid ; he 

 was not certain that they occur in arterial as well as in venous blood. See 

 also infra, p. 204. 



