ii] Circulation of the Blood, 51 



have been rejected as impossible, were now accepted without 

 misgivings. Indeed they afforded no little support to the new 

 theory of the circulation. 



Further support was supplied almost at the same time by 

 the publication in 1653 of the Nova exercitatio anatomica of 

 Olaus Rudbeck, Professor of Anatomy and also of Botany in 

 the University of Upsala (after whom is named the genus 

 Rudbeckia). In this treatise Rudbeck described under the 

 name of vasa serosa or aquosa, or ductus serosi, aquosi, vessels 

 like the lacteals in structure, but containing not milk, or chyle, 

 but a clear watery liquid, vessels which we now call lymphatics. 

 He saw them first in the liver and intestines and traced them 

 to the thoracic duct, of whose existence, he says, he became 

 aware in 1650 before the publication of Pecquet's book. We 

 learn from Glisson that one J olive, an Englishman, in taking 

 his Doctor's degree at Cambridge in 1652, presented in his 

 thesis an account of these same lymphatics, and by some 

 authors priority in the matter is thereby claimed for him. 



Within a few years then of the publication of Harvey's 

 book, anatomists became aware of a new set of vessels, of whose 

 existence no one before had dreamed, vessels neither arteries 

 nor veins, vessels containing not blood but either a milky or a 

 clear limpid fluid, and carrying their contents not to but away 

 from the tissues, carrying them moreover not to that great 

 organ the liver, which in the old view was the chief seat of all 

 concoction, but directly into the venous blood stream and so 

 to the heart, from thence to be distributed all over the body. 

 That such a conception almost at once found general accept- 

 ance is, as we have just said, a striking proof of how rapidly 

 and profoundly Harvey's work had influenced the views of 

 physiologists. 



When Aselli first discovered his lacteals he very naturally 

 concluded that all the chyle, the whole of the nutritive and 

 absorbable contents of the alimentary canal, found its way into 

 the system through them. It is interesting to note that Harvey 

 hesitated to accept this conclusion. In a letter to Morison 

 at Paris written in April 1652, a year after the publication of 

 Pecquet's treatise, he says, 



4—2 



