Trans. N. V. Ac. Sa. 80 Fed. 5, 



forward and upheld in this country, mainly by Drs. Carl Heitzmann 

 and Louis Elsberg. It is of this so-called theory, which at the most is 

 merely a hypothesis, that I desire to speak this evening. I shall rely 

 upon ocular proof to show that there is no reticulum in the blood cells. 



The microscope, like^every other instrument of research, requires to 

 be manipulated by a person of experience, to yield trustworthy and the 

 most perfect results. Yet there is a vast difference between the ability 

 to manipulate it and the ability to see what it reveals. Perhaps only 

 a small proportion of this audience could use the instrument fairly well ; 

 yet I doubt if there is one person here who could not see the most 

 minute details of any object, after the proper adjustments have been 

 made. 



We may consistently confine the discussion to three objects, viz., the 

 <imoeba, and the red and the white blood-corpuscles. As those who have 

 heard Dr. Elsberg's remarks before the Academy know very well, the 

 theory is, essentially, that all living tissues are constituted of a fine 

 net-work of very contractile, living matter, with inert matter filling the 

 meshes. It is not necessary to explain the theory more at length, 

 for the reason that the existence of such a net-work, readily seen by the 

 aid of a microscope, forms the foundation of every observation in sup- 

 port of it. Moreover, as the reticulum is said to be clearly visible in 

 all living matter, we have only to prove either that it does or does not 

 exist in the amcsba, or in a white blood-corpuscle, to sustain, or to utterly 

 refute the theory. 



I propose to demonstrate that there is absolutely no trace of 

 such a net-work in a blood-corpuscle. When the object-glass is 

 properly corrected and focused, no reticulum whatever can be 

 seen. In other words, the apparent reticulum which Dr. Heitz- 

 mann shows is, undoubtedly, the result of faulty observation of some 

 kind ; but probably the faults are not of a kind that a student or inex- 

 perienced microscopist would be able to detect, or to point out with 

 any assurance. It is said that the movements of a homogeneous jelly, 

 such as protoplasm has been described to be, would be impossible — 

 that some kind of reticulated structure is necessary to enable us to 

 explain its power of movement. At present it is merely a question 

 of fact whether there is a reticulum or not. After its existence has been 

 demonstrated it will be time enough to theorize how it enables us to 

 understand the phenomena of life. 



The reticulum is supposed to explain the movement of living matter ; 

 movement is due to contractility ; the contractility resides in the nodes 

 and connecting threads of the net-work ; the extension or contraction 

 of the net-work explains the movement of the amoeba and the blood- 

 cell. It is an ingenious, mechanical explanation of a mystery that has 



