438 ANNALS NEW YORK ACADEMY OF SCIENCES 



time any such abnormal appearance would be carefully preserved from being es- 

 teemed a sign of the purity and excellence of the breed; for on this principle the 

 Romans eighteen centuries ago valued the fifth toe and the white ear-lobe in their 



fowls." > 



But Mr. Darwin's cases of what we must regard as saltations are not 

 confined to the animal kingdom. We might easily cull from his list numer- 

 ous more or less pertinent examples under the peach, plum, cherry, grape, 

 gooseberry, currant, pear, apple, banana, camellia, Crataegus, azalea, hibis- 

 cus, althaea, pelargonium, chrysanthemum, dianthus, rose and perhaps 

 other plants. Concerning useful and ornamental trees he says: "All the 

 recorded varieties, as far as I can find out, have been suddenly produced 

 by one single act of variation," ^ and as to roses, he remarks on their marked 

 tendency to "sport" and to produce varieties "not only by grafting and 

 budding but often by seed," and quotes Mr. Rivers as saying that "when- 

 ever a new rose appears with any peculiar character, however produced, 

 if it yielded seed" he "expects it to become the parent of a new family." 

 In this connection Mr. Darwin called attention to the now well-known fact 

 that the mutative tendency is an inheritable one by citing the case of the com- 

 mon double moss-rose, imported into England from Italy about the year 

 1735, which "probably arose from the Provence rose {R. centifolia) by bud- 

 variation," the ^Vhite Provence rose itself ha^dng apparently originated in 

 the same way.^ He called attention also to the significant fact that many 

 abrupt variations were not to be attributed either to reversion or to the 

 splitting-up of hybrids. Thus he declares : 



"No one will maintain that the sudden appearance of a moss-rose on a Provence 

 rose is a return to a former state, for mossiness of the calyx has been observed in no 

 natural species; the same argument is applicable to variegated and laciniated 

 leaves ; nor can the appearance of nectarines on peach-trees be accounted for on the 

 principle of reversion." * 



In another place in the same work he says : 



" Many cases of bud- variation .... can not be attributed to reversion, but to 

 so-called spontaneous variability, as is so common with cultivated plants raised 

 from seed. As a single variety of the chrysanthemum has produced by buds six 

 other varieties, and as one variety of the gooseberry has borne at the same time four 

 distinct kinds of fruit, it is scarcely possible to believe that all these variations are 

 due to reversion. We can hardly believe .... that all the many peaches which 

 have yielded nectarine-buds are of crossed parentage. Lastly, in such cases as that 

 of the moss-rose, with its peculiar calyx, and of the rose which bears opposite leaves, 



1 " Animals and Plants Under Domestication," 2d ed., Vol. I, pp. 242-4. 



2 Ibid., p. 384. 



3 Ibid., pp. 405-6. 

 *Ibid., Vol. II, p. 242. 



