50 MAMMALIA. 



Dugong, on the contrary, they are greatly elongated ; occasionally 

 they appear incompletely lobed (in many Cats and Weasels), as in 

 the newly-born infant. In some animals, particularly those that live 

 in water, each kidney is divided into several, often into many lobuli. 

 In the Ox, there are found 20 free, rounded lobuli, about 12 in the 

 Otter, and from 40 to 50 in the Bear. The kidney is divided into 

 from 70 to 100 or more lobules in the Seals, and its surface has in 

 consequence a tessellated aspect. In the true Cetacea the kidneys 

 have a racemiform appearance ; in the Dolphins 200 separate lo- 

 bules can be counted. Each lobule is provided with a papilla, and 

 there is here found no pelvis, but an excretory duct proceeds from 

 each lobule, so that the ureter is composed of branched tubes, like 

 the ducts of other glands. Most of the remaining animals, namely, 

 all Apes, even the Orangs, most Rodentia, Carnivora, and Edentata, 

 have only a single papilla, into which all the renal tubuli open. The 

 urinary bladder is particularly large in the Herbivora (as in the 

 Horse), smaller, rounded and muscular in the Carnivora, thick-walled, 

 elongated, and very small in the Cetacea, whore the ureters also are 

 exceedingly short. 



The Renal capsules are generally present, and always larger in the 

 f(Etal than in the adult animal. They are flat, and like those of Man, 

 in the Quadrumana ; very large in most Rodentia, and very small in 

 the Cetacea, even in their fo3tus. 



SPECIAL SECRETING ORGANS. 



BESIDES the organs of secretion which are necessary for the gen- 

 eral animal economy, there occur in separate families, genera and 

 species, particular secretions, which always serve a special purpose 

 in connexion with the peculiar structure and mode of life of the ani- 

 mal to which they belong. 



Thus several of the Sebaceous follicles of the skin are developed in 

 many animals into compound follicles and true glands, which secrete 

 a strong smelling sebaceous or unctuous fluid. 



A group of such sebaceous sacs lies in the Stags and Antilopes in 

 a cavity of the lacrymal bone beneath the eye, which secrete what 

 are called the " tears of the Stag." 



The peculiar smell which emanates from the Cheiroptera depends, 

 for the most part, upon a considerable flat and yellow colored 

 gland, which in Vespertilio murinus, noctula, &c., lies upon both 

 sides of the upper jaw, between the eye and nose. Similar, only 



