162 SCIENCE PROGRESS. 



organ and its function. With his striving after physical 

 exactitude, there was no fear of his taking too narrow a 

 view of the activities of an organ, i.e., as a merely physical 

 apparatus. This one may illustrate by his researches on 

 muscle, which he regarded not merely as a physical 

 apparatus ; he took a far wider and more comprehensive 

 view, he regarded it as an organ whose histological 

 structure had to be investigated, and its physical characters 

 studied ; but even that was not enough, it had to be studied 

 from the point of view of how it comported itself when its 

 blood-vessels were perfused with blood, how its properties 

 changed as its nutrition altered, how it breathed, and how 

 its activities were affected by nervous and other influences. 

 Thus we must give a wide interpretation to his views of the 

 physical and chemical processes accompanying the mani- 

 festation of so-called vital phenomena. 



One very characteristic aspect of his work lay in his 

 strong morphological bias. The anatomical aspect of a 

 problem always attracted him greatly, and he always had 

 on hand some anatomical and histological investigation 

 from which he derived new inspiration for future physio- 

 logical research. The distribution of the blood-vessels 

 in various parts of the body had for him a peculiar 

 fascination, their relation to other tissues was ever present 

 to his mind. As a consequence we have the beautiful re- 

 searches on the origin of lymphatics ; the effects of the 

 respiratory movements on the movements of lymph ; his 

 theory of the mechanical results dependent on the distribu- 

 tion of the capillaries in the glomeruli of the kidney, and 

 how this affects the passage of fluids from the renal vessels 

 into the urinary tubules ; how the blood-vessels behave in 

 contracted and relaxed muscle. To what important dis- 

 coveries he was led by a study of the arrangement of 

 the heart muscle fibres we shall see presently. 



Dealing first with the researches published over his 

 own name, we have the classical paper " Beitrage zur 

 Lehre von Mechanismus der Harnsecretion," which he 

 presented to the Faculty in Marburg in 1842, when he 

 qualified as " Privat-docent " of physiology. In this con- 



