570 ANATOMY OF VERTEBRATES. 



the Mole the adrenals have the form of a three-sided pyramid. 

 In the Coypu they arc long and rounded, of a greyish-yellow 

 externally ; their medullary structure like soft liver. Their 

 length was one inch : their situation mesiad of the upper extremity 

 of each kidney. They have a similar cylindrical figure, and large 

 relative size in the Porcupine and many other Rodents : they are 

 shorter in the Muridce ; are roundish and somewhat flattened in 

 Leporithc. In a young Sloth I found the adrenal surpassing the 

 kidney in size, and showing distinctly the cortical and medullary 

 substances. In the Cetacea there is an interesting analogy between 

 the adrenal, in regard to its lobulated exterior, and the multi- 

 lobate kidney. In the Elephant the adrenal is a depressed cone, 

 with the base bilobed. In the Rhinoceros the adrenal bodies, like 

 the kidneys, differed from each other in form ; they were elongated 

 and nearly cylindrical. The right had one extremity bent at a 

 rio'ht an ode : its length in a female Rhinoceros was three and a 



?5 O t5 



half inches; its breadth across the bent extremity two inches: 

 the left was simply elongated, three and a half inches long, one 

 and a half bi'oad, and one inch thick. In section they presented 

 an external greyish-yellow fibrous cortex, from one-fourth to one- 

 third of an inch thick, enclosing a fleshy-coloured substance, in 

 the middle of which there was a semilunar portion of the grey 

 fibrous matter : there was no trace of a central cavity. Both 

 suprarenal bodies adhered closely to the contiguous large veins. 1 

 In the Horse the adrenals are flattened and triangular. In the 

 Ox they somewhat resemble the kidney itself in shape : in the 

 Reindeer they are a full oval : in the Sheep they 

 are more elongate. In the Seal, as in the Whale, 

 they resemble the kidney in their finely lobulate 

 exterior : in the Dog they are longish and cylin- 

 drical : in the Cat roundish and somewhat flattened. 

 In the Aye-aye the adrenals are subtriangular, 

 elongate, depressed, and relatively larger than in 

 the higher Quadrumana, in which the adrenals 

 progressively approach the shape and proportions 

 eight imcs prese nted in the human subject. 



(_ t_ .X > 1 1 . 



In the foetus the adrenal, like the kidney, shows 

 a lobulated exterior : at an early period of the development of 

 these bodies the adrenal, fig. 442, a, exceeds the kidney, b, in 

 size : both are preceded by the deciduous or Wolffian kidneys, 

 d y d. In the embryo of the twelfth week the kidneys and adrenals 



1 en", p. 4o, pi. xii, fig. 1, )), n. 



