492 



KIDNEY. 



[CHAP.XXXTV. 



over which they spread. 



Fig. 237. 



From these arteries smaller branches 

 are given off, which ascend in the 



cortical substance nearly to the sur- 

 face, and, in so doing, give off, on all 

 sides, a number of small terminal 

 twigs, the afferent vessels of the Mal- 

 pighian bodies. Arrived within the 

 capsule, the small afferent vessel at once 

 divides into four or five branches, each 

 of which again divides dichotomously. 

 The small capillary vessels form loops, 

 which project towards the opening of 

 the uriniferous tube. The blood is re- 

 ceived from these vessels, which lie 

 towards the outside of the tuft, by 

 branches of the efferent vessel which 

 converge towards the more central part 

 of the tuft to form one trunk, which 

 leaves the Malpighian body, and soon 



Malpighian tuft, from near the base of breaks Up into a pleXUS of Capillary 



one of the medullary cones, injected . . . - ,, , . , , 



without extravasation, and showing the VCSSClS, in the mCShCS OI WlllCh the 



efferent vein branching like an artery as , ... mi , . , . 



it runs into the medullary cone. o.Ar- tubes lie. The terminal arterial twigS 



terial branch, a f. The afferent vessel. ... , . , , f , , . . -, 



m m. Malpighian tuft, ef. The efferent with their appended tufts, when injected 



vessel, b. Its branches entering the .., -T i -L i 



medullary cone. Magnified about 70 with vermilion, have been compared not 



inaptly to a bunch of currants. 



The size and complexity of the Malpighian bodies differ much 



in different animals, according to the activity of the function they 



/ty.238. are called upon to 



discharge. The ves- 

 sels present fewer 

 convolutions, the 



*/ Wi tufts are smaller, 

 and their arrange- 

 ment much simpler 

 in those animals, in 



From the parrot ; injected by the artery, a, a, a. Terminal branches which the Urine is 

 of the artery, af, af, uf. Terminal twigs of the artery, d. Dilatation 



of the terminal twig on entering the Malpighian capsule, m. This di- almost of a Solid 

 latation more completely filled, showing its convoluted form ; and ef, 

 ef, the efferent vessel, c. The Malpighian capsule filled by extrava- 

 sation from the contained vessel, and the tube t likewise filled. Mag- 

 nified about 80 diameters. 



consistence. Com- 

 pare the complicated 

 arrangement in the horse and other mammalia in Figs. 236 and 

 237, with the few arid simple convolutions in birds, Fig. 238. 

 By reference to'the following table, it will be seen that the diameter 



