THE BEAVER.

1413

diverge outwards and towards the pubes. Each castor sac is composed of an externalor cellular coat which incloses muscular fibres. The latter are a continuation of thefaiiniculus carnosus: their function appears to he to compress the sac. Within these,lbr es lies a very vascular coat, which covers the scaly or glandular coat, and sends^ pro-' ess es i„ between the convolutions of the latter The scaly or glandular coat forms* lu merous folds or convolutions, which are largest and most numerous in the tundus ot>e sac. Externally, it is shining, silvery, and iridescent. Internally, it presents'unierous, small, lanceolate, oblong, or semilunar scales, which are mostly toothed atJ h eir margin, and envelope each a brown body, supposed to be a gland, and which is*°dged in a small cavity. The inner surface of the castor sacs is lined with epithelium;? Co, 'tinuation of the epithelium of the prepuce), which invests the glands and scales ofhe sca i y 0r glandular coat. In the cavity of the castor sac is found the castorenm,7‘cli, when recent, is thin, fluid,highly odorous,yellow or orange coloured, becomingTi eper b y exposure to the air. The quantity of this secretion is liable to great variation.

oil sacs a re conglomerate glands, placed one on each side between the castor sac* ui anus ; their ducts terminate in the cloaca. The secretion of these sacs ,s a fattyhaving the consistence of syrup or honey, a peculiar odour, and a yellowishr our - It was formerly used in medicine under the name of pmguedo seu ammgial^toris. (For further details respecting the structure of the castor sacs consult Brandt

“ R atzeburg, Med. Zool. i.)

Fig. 278.

Fig. 277.

Castor and oil sacs laid open.

I

* e - Analta^or sacs.

glands.

t< ’p Co , w per’s glands.

’ , robe nassiug into the rectume "eatn a semilunar fold whichS( j,I>arates the common aperture0 the castor sacs from thePenis .

att

Relative position of the castor and oil sacsandpelvis.

a a. Os pubis.b, Bladder.cc. Castor sacs.d d. Oil sacs.

/, The false cloaca.g, The commencement of the penis.h h, The epididymides.i i. The testicles.k k, The spermatic cord.

11, The vasa deferentia.

__ mm. The cremaster muscles.

,ll k>iss e i! at * Ve -P os ‘ t ' on op tbe castor and oil sacs, with respect to the pelvis of the ani-2. Q p eWn ht fig. 278, taken from Perrault (op. supra cit.)

W, * 11B Female Castor Sac.— We are less perfectly acquainted with thethe female than of the male heaver. Indeed I am acquainted with three

veins.

and Two p ro h e s passing intoright castor sac, behind asecond semilunar fold.

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