For some occult reason they are provided with a gland charged with a malodorous secretion; and out of this mysterious liquor Nature has elaborated the skunk's inglorious weapon. The skunk alone when attacked makes no attempt to escape or to defend itself by biting; but, thrown by its agitation into a violent convulsion, involuntarily discharges its foetid liquor into the face of an opponent. When this animal had once ceased to use so good a weapon as its teeth in defending itself, degenerating at the same time into a slow-moving creature, without fear and without cunning, the strength and vileness of its odour would be continually increased by the cumulative process of natural selection: and how effective the protection has become is shown by the abundance of the species throughout the whole American continent. It is lucky for mankind--especially for naturalists and sportsmen--that other species have not been improved in the same direction.
Humble-Bees and other Matters. 59
But what can we say of the common deer of the pampas (Cervus campestris), the male of which gives out an effluvium quite as far-reaching although not so abominable in character as that of the Mephitis? It comes in disagreeable whiffs to the human nostril when the perfumer of the wilderness is not even in sight. Yet it is not a protection; on the contrary, it is the reverse, and, like the dazzling white plumage so attractive to birds of prey, a direct disadvantage, informing all enemies for leagues around of its whereabouts. It is not, therefore, strange that wherever pumas are found, deer are never very abundant; the only wonder is that, like the ancient horse of America, they have not become extinct.
The gauchos of the pampas, however, give a reason for the powerful smell of the male deer; and, after some hesitation, I have determined to set it down here, for the reader to accept or reject, as he thinks proper. I neither believe nor disbelieve it; for although I do not put great faith in gaucho natural history, my own observations have not infrequently confirmed statements of theirs, which a sceptical person would have regarded as wild indeed. To give one instance: I heard a gaucho relate that while out riding he had been pursued for a considerable distance by a large spider; his hearers laughed at him for a romancer; but as I myself had been attacked and pursued, both when on foot and on horseback, by a large wolf-spider, common on the pampas, I did not join in the laugh. They say that the effluvium of C. campestris is abhorrent to snakes of all kinds, just
16o The Naturalist in La Plata.
as pyrethrum powder is to most insects, and even go so far as to describe its effect as fatal to them; according to this, the smell is therefore a protection to the deer. In places where venomous snakes are extremely abundant, as in the Sierra district on the southern pampas of Buenos Ayres, the gaucho frequently ties a strip of the male deer's skin, which retains its powerful odour for an indefinite time, round the neck of a valuable horse as a protection. It is certain that domestic animals are frequently lost here through snake-bites. The most common poisonous species--the Craspedo-cephalus alternatus, called Vivora de la Cruz in the vernacular--has neither bright colour nor warning rattle to keep off heavy hoofs, and is moreover of so sluggish a temperament that it will allow itself to be trodden on before stirring, with the result that its fangs are not infrequently struck into the nose or foot of browsing beast. Considering, then, the conditions in which C. campestris is placed--and it might also be supposed that venomous snakes have in past times been much more numerous than they are now--it is not impossible to believe that the powerful smell it emits has been made protective, especially when we see in other species how repulsive odours have been turned to account by the principle of natural selection.
After all, perhaps the wild naturalist of the pampas knows what he is about when he ties a strip of deer-skin to the neck of his steed and turns him loose to graze among the snakes.
The gaucho also affirms that the deer cherishes a wonderful animosity against snakes; that it be-