1874.] On the Minute Anatomy of the Alimentary Canal. 293 



the same distance which can be expressed in other terms by saying that 

 the length of the first cardio-radial interval, from which that of the 

 syspasis has been subtracted, ought to be exactly the same as that of the 

 second cardio-radial interval. That such is the case is proved by the 

 measurement of the lengths of these two intervals independently ; and 

 it is found that in all cases they agree to three places of decimals, which 

 is great evidence in favour of the accuracy of the methods and arguments 

 employed. 



The latter part of the paper is occupied with the description of, and the 

 results obtained by, the employment of a double sphygmograph, by means 

 of which simultaneous tracings are taken from two arteries at different 

 distances from the heart. The arteries experimented on are the radial 

 at the wrist and the posterior tibial just behind the ankle, 29 and 52-5 

 inches respectively from the aortic valves. From the resulting tracings, 

 the time occupied by the pulse-wave in travelling the difference of 

 distance (52-5 29 = ), 23-5 inches, is found and stated to be 0-0012 of a 

 minute in a pulse of 75 a minute ; and it is shown that this varies very 

 little with differences in pulse-rate, as might Have been previously ex- 

 pected; it is also proved that there is an appreciable acceleration of the 

 movement of the pulse-iuave as it gets further from the heart. 



By superposing the simultaneous trace from the wrist on that from 

 the ankle, direct verification is obtained of the earlier proposition that 

 the sphygmosystole at the wrist and that at the ankle are of exactly similar 

 duration. The peculiarities of the ankle-trace are also referred to. 



II. "Note on the Minute Anatomy of the Alimentary Canal." 

 By HERBERT WATNEY, M.A. Cantab. Communicated by Dr. 

 SANDERSON, F.R.S., Professor of Practical Physiology, Uni- 

 versity College. Received March 10, 1874. 



The following results relating to the anatomy of the mucous membrane 

 of the alimentary canal were obtained in the laboratory of the Brown In- 

 stitution. The researches were carried out under the direction of Dr. 

 Klein. 



1. Connective-tissue corpuscles amongst the epithelium. In specimens 

 hardened in chromic acid and alcohol and stained in hsematoxylin, 

 structures are constantly seen among the columnar epithelium of 

 the intestinal tract in many animals (as monkey, sheep, cat, dog, 

 rat, rabbit) which belong to the connective tissue. These are : 

 (1) a delicate reticulurn, which is continuous with that formed by the 

 most superficial layer of connective-tissue corpuscles (the basement 

 membrane) ; (2) round nucleated cells, exactly similar to those of the 

 mucosa. 



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