and the South American C. rufus, C. simplicicornis, have antlers more or less in the condition of 'dags' at all ages. If a Fallow-buck, with antlers, be castrated, they are shed earlier than usual, and by a more active absorbent process, which leaves an irregular concavity at the base: the antlers that are subsequently developed are small, seldom branched, retain the 'velvet' longer than usual, and become thickened by irregular tuberculate masses of bone. If a young buck be castrated before it has put up' antlers, it does, afterwards, in some instances, develope them, but of reduced size and abnormal shape, retaining them, with their formative covering, longer than usual. Occasionally, though rarely, they are shed and renewed: but such shed antlers of a heavier' or castrate deer are characterised by the excavation of their base. The normally shed antlers of perfect males have the base flat or convex, and almost smooth. A rare instance of the sexual relation of antlers, the coincidence, viz. of a small one with a diseased ovary of the same size, in a fallowdoe, has been recorded.2 In most deer the antlers are supported on permanent processes, or 'pedicels,' varying in length in different species, and attaining their greatest in the Muntjac (Cervus Muntjac, vol. ii. p. 478, fig. 328), which thus seems to shed only half its horns. The persistent integument of such pedicels is always defended by the burr (ib. b), below which the absorbent process takes place at the shedding period. Thus Deer are the only Ungulates that annually shed their horns: the Prong-buck is the only known hollow-horned Ruminant that annually sheds the extravascular part of the horn, called the sheath.' The horns of Ungulates may be summarised as consisting either of horn only (Rhinoceros), of bone only (Cervus), of horn and bone (Bos), or of skin and bone (Camelopardalis). 1 Redi's dictum :- Si cervus juvenis castretur, nondum emissis cornubus, cornua nunquam emittit: si castretur jam emissis cornubus, cornua nunquam mutat; sed quæ dum castratur habet, castratus semper retinet' (ccxxvir". p. 162):—is adopted by Buffon: Si l'on fait cette operation dans le temps qu'il a mis bas sa tête, il ne s'en forme pas une nouvelle; et si on ne la fait au contraire que dans le temps qu'il a refait sa tête, elle re tombe plus; l'animal, en un mot, reste pour toute sa vie dans l'état où il était lorsqu'il a subi la castration,' cxx'. tom. vi. p. 81. The experiments (XLIV. pp. 590, 591), which Sir Philip de M. Grey Egerton, Bart., was so kind as to have made, at my suggestion, on Fallow-deer, in Oulton Park, yielded in the main the results given in the text. It is desirable that similar experiments should be repeated in the Red-deer. Two males of Rein-deer, said to be castrates, at the Zoological Gardens, and which have never shown sign of rut, have shed and reproduced antlers of normal form, and nearly full size during three consecutive years. 2 CCXLIII", p. 356. CHAPTER XXXVI. PECULIAR GLANDS OF MAMMALIA. MOST species of the Mammalian class have their peculiar odour, whereby, mainly, the individuals of such recognise each other; and, in the gregarious kinds, a stray one may be guided to the herd by scenting the secretion which has been left upon their track. Such odours are commonly due to follicles or glands opening upon some parts of the skin; but there are, likewise, glands subserving other uses, peculiar to certain species. § 365. Opening upon the head.-In many Ruminants and some hogs, a depression or inverted fold of skin, near and usually anterior to or below the orbit, is perforated by the ducts of numerous more or less developed sebaceous follicles, discharging their secretion into the cavity. As this is often placed so as to receive an overflow of the lacrymal secretion, and as a corresponding depression is usually present in the large facial plate of the lacrymal bone, it has been termed by French naturalists larmier: by English writers, the tegumentary sac, with its glands and muscles, is called 'suborbital pit or sinus.' In the Indian Antelope (Antilope cervicapra), it is large and deep: a few short hairs project between the glandular orifices at the bottom of the sac: its circumference is entire and provided with radiating and circular strata of muscular fibres on the surface next the depression of bone in which it lies: by these muscles the tegumentary pit can be expanded, contracted, protruded, and partially everted, whereby the glandular surface may be brought into contact with and rubbed against foreign bodies: the follicles are multilocular and numerous in this species. The odour of the secretion, inclining to musky, may be recognised by a stray individual of a herd, or by the doe, which might thereby be guided to her mate. The gland seems most nearly to relate to the sexual function: it is usually larger in the male than the female, and its development is checked by castration. It is present, but small, in most goats and sheep; also in many deer,' in which it appears as a simple fissure continued from near the lacrymal angle of the eye. A similar pit occurs in a more advanced position in some antelopes; such maxillary pits' sometimes co-exist with the suborbital ones, sometimes replace them. A third position of the cutaneous gland-pit is more rare, viz. behind the base of the ear, as in the Chamois (Antilope rupicapra). With a view to test the relation of these organs to the habitats, and gregarious or solitary habits of the Antilopida, I drew up the subjoined table2: Antilope Sumatrensis. Hab. hilly forests; habits of the Goat. quadriscopa. Senegal. cervicapra. Open plains of India; gregarious. melampus. Open plains of Caffraria; flocks of six or eight. picta. Dense forests of India; small herds. scoparia. Open plains of S. Africa; subgregarious. melanotis. Plains, hides in underwood; in pairs. Mhorr. Deserts of Morocco. ruficollis. Deserts of Nubia; gregarious. Antilope colus. Vicinity of lakes; gregarious, migratory. gutturosa. Arid deserts, Asia; periodically grega rious. 'Antilope Saltiana. Mountainous districts, Abyssinia; in pairs. Oreotragus. Mountains of the Cape; sub-gregarious. Thar. Hills of Nepaul; not gregarious. Gazella. Senegal. Antilope Babalus. Mountains and deserts, Tripoli; gregarious. Caama. Plains of S. Africa; gregarious. lunata. S. Africa; gregarious. Gnu. Karroos of S. Africa; gregarious. taurina and Gorgon. S. Africa; gregarious. Antilope silvicultrix. Thickets and underwood, Africa; Guinea. Burchellii; S. Africa, in pairs. perspisilla. Bushes, S. Africa; in pairs. Pygmæa. 1 xx. vol. iii. p. 272, no. 2101 (Cervus tarandus). ib. 2 ccxxxш". p. 37. ? No suborbital, ́ ́ Antilope Strepsiceros. Woods and banks of rivers, Caffraria; or maxillary pits. Post auditory pits. No suborbital, or maxillary pits. Inguinal pits. No inguinal pits. subgregarious. sylvatica. Woods, Caffraria; in pairs. scripta. Koba. Senegal. Kob. Senegal. Eleotragus. Reedy banks, Cape; subgregarious. capreolus. Underwood, S. Africa; subgregarious. Landiana. Underwood, S. Africa; subgregarious. leucoryx. Acacia groves, N. Africa; gregarious. equina. Plains, S. Africa; gregarious. Oreas. Open plains, S. Africa; gregarious. Goral. Elevated plains, Himmalay; gregarious. From the foregoing summary it may be inferred that the scented secretion of the suborbital sinus serves rather to attract or guide the female, than a stray individual of a herd. In the African Water-hogs a naso-maxillary pit opens between the eye and snout, rather nearer the eye. In the Elephant a large gland of a flattened form and multilobate structure, lies beneath the skin of the face, in the temporal region the secretion exudes from a small orifice, situated about half way between the eye and ear. The gland enlarges, in the secretion then has a strong male, at the rutting season, and the musky odour. $366. Opening upon the trunk. In certain tropical bats (Cheiromeles torquatus, Cheir. caudatus, e.g.) a glandular sac exudes upon the forepart of the breast, near the axilla, a brownish sebaceous secretion of a penetrating submusky odour. In many Shrews two longitudinal series or groups of glandular tubes, open upon the flanks, at a part surrounded by short hairs; the tubes are tortuous and closely conglomerated at their blind ends, but become straighter near their termination. The peculiar odour, more or less musky, of Soricidæ, is due to the secretion of these glands, and makes the shrew-mouse unacceptable as food to the cat that may have killed it. In the Peccari, a large gland, fig. 496, consisting of many lobes, exudes its secretion by an orifice, ib. b, on the midline toward the hinder part of the back. The resemblance of this orifice to the navel on the opposite part of the trunk suggested to Linneus the term Dicotyles, for this genus of S. American porcine animals. In many Antelopes there are situated in the groin, external to the nipples in the females, glandular depressions of the skin, or pouches, sometimes of large size, as in Antilope corinna, e.g., in which the secretion is yellow, like cerumen.' The presence or absence of the groin-pits in the different species of Antelopes is noticed. in the table, p. 633. The most notable development of scent 496 glands and bags, at the groin, are those which open into the prepuce of the small Ruminant, called on account of the odour of the secretionMusk-deer' (Moschus moschiferus). The fully 497 developed gland at the fundus of the sac may be three inches in diameter and one inch at its thickest part; the moist secretion accumulates in the cavity of the tegumentary pouch, and constitutes, when dried, the costly medicament or perfume, musk.' The analogous carminative or antispasmodic substance castoreum' is the secretion of glands, fig. 497, exuding into the preputial and ano-preputial passage of the beaver. They present the appearance of two large masses, with a common muscular investment on each side the dorsal tract, which is unusually prolonged beyond the pelvis for their accommodation in that rodent. On re moving the muscular layer, Preputial and glands of the Beaver. each mass has its capsule: on dissecting this away, the upper mass 1 CCXXXVI. vol. ii. p. 146. |