THE URINARY ORGANS. 601 



The ciliary motion discovered by Bowman in the neck of the Mal- 

 pighian bodies of the Frog, and in the commencement of the tubuli 

 uriniferi, with the direction of the stream towards the ureter, is readily 

 confirmed, when the addition of water is avoided. It is absent, how- 

 ever, in Birds (Gerlach thinks he has seen it on one occasion in the 

 Fowl) and other Mammalia, and was not noticed by me in the cases of 

 two executed criminals, examined especially with respect to this point, 

 whilst it is found in Serpents, in the Salamander, Triton, Bombinator, 

 Bufo, and is very well marked in Fishes, and also, according to 

 Remak's and my own observations, in the Wolffian bodies, which have 

 the structure of kidneys, in the embryo of the Lizard ; in the last two 

 instances they are also met with in the uriniferous ducts at a greater 

 distance from the Malpighian bodies. 



Of the very numerous pathological degenerations of the tubuli urini- 

 feri, I will notice only the following : The membrana propria is fre- 

 quently thickened to O'OOl, or even 0*002 of a line, when it often 

 presents, on the inner aspect, very delicate, closely approximated trans- 

 verse striee. The epithelial cells, particularly in the cortical substance, 

 frequently contain oil-drops in considerable quantity, so as often to 

 present a deceptive resemblance to the cells of a fatty liver, and at the 

 same time they are usually enlarged to a diameter of 0'02 of a line. 

 Together with the oil, pigment granules (of the coloring matter of 

 urine ?) occur in them (also in the straight canals), whereas the concre- 

 tions of uric acid and calcareous salts, which are so frequently met 

 with in the canals of the tubules in the Vertebrata have not as yet 

 been demonstrated with certainty in the cells themselves (in Fishes, 

 Simon, " Thy mus" p. 69, often found crystals in the renal cells). 

 Colloid-like, bright yellow masses are frequent in the epithelial cells, 

 which then most usually increase in size, dilate into slender cysts as 



apparent discrepancy of opinion among anatomists. Bowman states that each tube com- 

 mences in a Malpighian capsule; whilst Gerlach says that the capsules do not form the 

 extremities of the uriniferous tubes, but are merely diverticula, which communicate by a 

 small neck with the angle formed by the uriniferous tubes, winding through the cortical 

 part of the kidneys; or, as the same thing is described by Leydig (1. c., p. 32), with respect 

 to the kidney of the Sturgeon, two closely contiguous, uriniferous tubules, are connected with 

 the (Malpighian) capsule and continuous with it; in other words, the tubules join in a loop, 

 at the apex of which is a globose diverticulum, in which the glomerulus is lodged ; and 

 according to him, the same arrangement obtains in the Reptilia. Now it seerns that this 

 discrepancy admits of an easy explanation, for if we suppose the constricted neck of the 

 diverticulum to be lengthened into a tube, we have at once the disposition described by 

 Bowman, viz. : a tube commencing in a dilatation containing the glomerulus and afterwards 

 anastomosing with another or with other tubules; and if the neck of the so-called diverti- 

 culum be very short, or, in other words, if the Malpighian capsule be sessile, we have the 

 arrangement described by Gerlach, &c. Mr. Toynbee's notion that the tubulus uriniferus 

 merely passes through the Malpighian capsule, forming a coil within it, appears to us to be 

 wholly inadmissible; but many of the appearances depicted in his very carefully-executed 

 figures (1. c.) would serve to support the opinion that the Malpighian body is more often 

 sessile than it would seem to be from Bowman's account. TRS.] 



