TEANSACXIONS OF SECTION D. — DEPT. ANATOMY AND THTSIOLOGY. 565 



(»r of anomalous kind (as those of the thymus and thyroid body), are lined with 

 an epitbeliiiin.' 



As a result of his anatomical studies on the kidney, Mr. Bowman was led to 

 frame a theory of renal secretion, which, though opposed for a time by a master 

 mind, has, by the progress of research, received complete confirmation, and which 

 was based in no small degree upon the new yiews of the function of epithelial 

 cells in glands. The Malinghian body. Bowman showed, is the dilated commence- 

 ment of a convoluted tubule, and, like it, presents a delicate, structureless, base- 

 ment membrane. Into the Malpighian body projects a tuft of capillary vessels, 

 continuous, on the one hand, with an afferent vessel derived from a branch of the 

 renal artery, on the other, with an efferent vessel of smaller size than the afferent ; 

 both afferent and efferent vessels piercing the capsule of the Malpighian body ; after 

 leaving the glomerulus, the etFerent vessel breaks up into a series of capillaries, which 

 are distributed to tlie walls of the convoluted tubes. The tuft of blood-vessels pro- 

 jecting into the Malpighian body, Bowman described as being perfectly bare, that is 

 to say, not covered by a basement membrane, or by a layer of epithelium cells. 

 This part of his description lias not been confirmed by recent work, the more 

 delicate nu'thf)ds of modern histology allowing of a ready demonstration of a 

 layer of cells of extreme tenuity coveriiig the glomerulus. 



The basement membrane of the convoluted tube was described as lined by a 

 nucleated epitlielium of a finely granular opaque aspect; the neck of the tube, 

 where it joins the Malpighian capsule, and the contiguous portions of the capsule 

 were described as covered by a layer of cells, differing altogether from the first, 

 being much more transparent, and possessing in certain animals vibratile cilia. In 

 some cases the whole interior of the capsule was lined by epithelium cells of great 

 delicacy and tenuity; in others, these cells could not be traced over more than a 

 third of the capsule. Basing himself upon the altogether exceptional arrangement 

 of the blood-vessels of the glomerulus, Bowman advanced the theory that this is a 

 structure destined to separate from the blood its watery portion. The epithelium 

 of the convoluted tubes, on the other hand, which Bowman pointed out to be 

 ' eminently allied to the best marked examples of glandular epithelium,' he believed 

 to be concerned in the separation of the characteristic solid matters of the renal 

 secretion. 



I shall for the present conclude my remarks upon Mr. Bowman's investigations 

 and theoretical views by stating that, by his investigations of the blood-supply 

 to the kidney of the boa constrictor, he gave the strongest proof which could be 

 derived from anatomical evidence of the correctness of liis views, and furnished 

 '-,'reat part of the knowledge required for the subsequent researches which Nussbauni 

 made on the secretion of the newt's kidney, and which afforded the most con- 

 clusive experimental evidence in favour of the theory which Bowman had 

 advanced. 



The Discoveries of Gael Ludavis. 



If to Johannes Miiller we must ascribe the greatest share of merit as a discoverer 

 of the general affinities, relationships, and functions of glands, it appears unques- 

 tionable that to C-'arl Ludwig belongs the credit of having, above all others, brought 

 the light of experimental physiology to bear upon the subject of secretion. 



Ludwig is one of the most eminent of the physiologists who have endeavoured, 

 so far as possible, to apply the conceptions derived from a study of physical and 

 chemical processes in general, to the elucidation of the functions of the organism. 

 More than anyone else has he successfully adapted the methods of research of the 

 chemist and of the physicist to the investigation of the problems which lay before 

 him. Above all others he is to be spoken of as the great teacher amongst all of 

 tlie great teachers of physiology which this century has produced. If we try to 

 find one who, from the fertility of his mind and the influence which be had upon 

 men of ability, affected the progress of his science in like measure to Ludwig, 

 we revert to the name of Liebig. When I say that physiology owes as much to 

 Ludwig as chemistry to Liebig, I shall, I feel sure, be doing but scant justice to 



