590 CLASS XVII. 



suspended, according to tlie discovery of BoWMAN, in dilatations, 

 which are the blind extremities of the secreting tubes'. In the 

 human embryo the kidneys consist of several masses or lobes ; in 

 some animals they continue in this form during the whole life, as 

 in the carnivorous Cetacea, the seals, the bears. A urinary bladder 

 always exists in this class, and the two tireters open into it. It 

 appears to be smaller in the carnivorous than in the herbivorous 

 animals. The so-named accessory kidneys {capsulce renales, renes 

 succenturiati) lie at the upper part of the kidneys; in the foetus 

 they are proportionally larger than in the adult. The function of 

 these organs is unknown, but does not appear to have any relation 

 to that of the kidneys. 



There are two ovaries in mammals. In the duck-mole the 

 right ovary is small and imperfect, which indicates a conformity 

 with birds (see above, p. 347). In its tissue Oraafian vesicles 

 are found, on the structure of which we have already spoken above 

 (p. 5). The size of the ovaries appears to have no direct rela- 

 tion to the fertility of the animal species. The oviducts are usually 

 very narrow in mammals, and here bear the name of Fallopian 

 tubes. The uterus and the oviducts are organs of the same kind 

 and of the same texture; originally, therefore, the uterus is entirely 

 double; it has two horns, and at the points of the so-named horns 

 the oviducts are implanted. This condition which is transitory in 

 the human foetus persists in some mammals for the whole life; 

 thus in the Monotremes, the Marsupiates, tlie Rodents, the uterus 

 is double, and has two openings into the vagina, or in the most the 

 uterus is two-horned, and the mouth and neck only are single; in 

 the apes alone the uterus has an undivided /tint^i^s as in the human 

 body. The muscular tissue of the uterus resembles the muscular 

 tunic of the intestinal tube and of the urinary bladder. The abdo- 

 minal aperture of the Fallopian tubes is usually widened like a 



^ Compare on the internal structure of the kidney A. Schumlanskt Diss, inaug. 

 anat. cle strucfiu-a Renum, Argentorati, 1782, 4to; jEm. Huschke Ueier die Textur 

 der Niere in Oken's Ids, 1828, s. 560 ; Mueller De glandidaruvi striiciura penitiori, 

 Lipsite, 1830, fol. pp. 94—102; W. Bowman Phil. Trans. 1842, Pt. i. pp. 57 — 80. 



See also the interesting explanation of Hyrtl (a proof of pure love of truth) Lehr- 

 buck der Anatomic des Menschen, 3te Auflage, 1853, s. 538. Gerlach adopts a lateral 

 insertion also of these capsules (as though they were eversions of the secreting tubes) ; 

 see his researches in Mueller's Archiv, 1845, 1848, and Hamlbuck der Getvebelchre, 

 Mainz, 1850, s. 297, 306. 



