Page:The Zoologist, 4th series, vol 6 (1902).djvu/210

168 trace in a gaseous form of a drop of oil of roses Great variety is found in the scent of distinct roses. Kerner and Oliver state that the various species of the rose genus may be recognized at once by their peculiar scent. The perfume of Rosa centifolia is the one which in particular is understood by the rose-scent, but it is very different from that of R. alpina; and the latter, in its turn, is unlike any of the scents emitted by R. arvensis, R. gallica, R. indica, &c. R. nasterana has a scent strongly resembling that of pinks, while R. lutea and R. punica are notorious for their disagreeable smell. Now the hybrid roses emit odours in which the scents of the parent species are merged together in a great variety of ways. Usually the scent of the stock predominates, and there is only a suggestion of the other. Sometimes, however, an entirely new scent is evolved from the fusion of the two, as in the case, for instance (according to Macfarlane), in Hedychium sadlerianum, the hybrid between H. gardnerianum and H. coronarium; and, again, in other cases, one of the component odours is intensified, and the other is extinguished ('Natural History Plants,' vol. ii. p. 566).—If we may consider the different scents as at all equivalent in number to the different races or varieties of roses, then we are face to face with a most complicated phenomenon; for, according to the previously quoted authorities, on an average, sixty newly-bred roses come into the market yearly; in the year 1889 the number even amounted to 115! A rose cultivator at Meidling, near Vienna, grows in his garden nearly 4200 different kinds of roses, and yet he is still far from possessing all the forms which have been produced in recent times (chiefly by French growers) by crossing one with another. According to his estimate, the number of tea and Indian roses alone is nearly 1400, and the total number of all the different roses which the trade has produced up to the present day (1895) amounts to 6400. It would certainly appear that the scents emitted by plants are not universally of an attractive purpose. "The scent which the mosses exhale is found in no other group of plants. The same is true of ferns" (ibid. p. 615). is sufficient to produce in our nostrils the impression of a pleasant odour. The smallest particle of musk is capable of imparting its characteristic smell to our clothes for years, the strongest current of air being insufficient to drive it away; and Valentin has calculated that we are able to perceive about the three-one-hundred millionth of a grain of musk. The delicacy of our sense of smell thus far surpasses that of the other senses. If, on the other hand, the evil smelling properties of the Skunk —the enfans du diable of Gabriel Sagard-Théodat —tend to make it avoided by animals