8 BIOLOGICAL PHYSICS 



principle of circulation as an organic modus vivendi on a 

 platform of absolutely demonstrable truth. 



A somewhat similar dilemma befell him at an earlier 

 stage of his investigations when brought face to face with 

 the linking of the pulmonary and general blood circulation 

 and their relationship to the phenomena of a unal or undi- 

 vided circulation, under the control and by the divisional 

 operation of the powers resident within the four chambers 

 of the heart. 



In solving this problem his methods and efforts met 

 with entire success, subsequent discovery in this field 

 having but more firmly established his title to full confi- 

 dence and respect. 



Since the great principle of circulation has had time 

 to work out under the constantly increasing band of 

 anatomical and physiological discoverers, and practical 

 workers in the domains of related science, it cannot be 

 gainsaid that great advances have been obvious through- 

 out the whole domain of biological science, and that 

 circulation after circulation has been added to the proved 

 realities of the human organism, giving it the appearance 

 of a combined system of circulations, the one hanging 

 on and united to the other with the completeness of a 

 transcendental continuity and oneness. 



When examining this collection of circulations with a 

 view, so far as we could, to attempt the appreciation of 

 the tout ensemble of the circulatory chain, we have been 

 struck with the existence of missing links, such as this 

 which exists between the circulation of the blood proper 

 and the related haemal lymphatic circulation. 



Within this area occur a series of circulations culmin- 

 ating in the assimilative, nutritional, or metabolic, which 

 has not by any means been fully explored, and which 

 therefore still calls for effort to place it on the level which 

 has been so long characteristic of the other areas of the 

 great subject. 



On asking the following questions How does the 

 blood reach the lymphatic vasculature, and what circu- 

 latory experiences does that portion of it which becomes 

 lymph undergo, previous to its entering that vasculature? 

 we shall attempt an answer to the latter question first, in 



