Chap. XIV. PREPOTENCY OF TRANSMISSION. 43 



K nearly all the characteristics of the white-flowered and white- 

 " seeded varieties ; and this result follows whether these varieties 

 " have been used as the pollen-bearing or seed-producing parents." 



The law of prepotency comes into action when species are crossed, 

 as with races and individuals. Gartner has unequivocally shown 15 

 that this is the case with plants. To give one instance: when 

 JS'icotiana paniculata and vincaejiora are crossed, the character of 

 J\ T . paniculata is almost completely lost in the hybrid; but if N. 

 quadrivdlvis be crossed with N. vincceflora, this latter species, 

 which was before so prepotent, now in its turn almost disappears 

 under the power of JV. quadrivalvis. It is remarkable that the 

 prepotency of one species over another in transmission is quite in- 

 dependent, as shown by Gartner, of the greater or less facility with 

 which the one fertilises the other. 



With animals, the jackal is prepotent over the dog, as is stated 

 by Flourens, who made many crosses between these animals ; and 

 this was likewise the case with a hybrid which I once saw between 

 a jackal and a terrier. I cannot doubt, from the observations of 

 Colin and others, that the ass is prepotent over the horse ; the pre- 

 potency in this instance running more strongly through the male 

 than through the female ass; so that the mule resembles the ass 

 more closely than does the ninny. 16 The male pheasant, judging 

 from Mr. Hewitt's descriptions, 17 and from the hybrids which I 

 have seen, preponderates over the domestic fowl ; but the latter, as 

 far as colour is concerned, has considerable power of transmission, 



13 ' Bastarderzeugung,' s. 256, 290, and this is generally accounted for 

 &c. Naudin (' No uvelles Archives du by the males of both species trans- 

 Museum,' torn. i. p. 149) gives a mitting with greater power this part 

 striking instance of prepotency in of their structure ; but a compound 

 Datura stramonium when crossed with hybrid which I saw in the Zoological 

 two other species. Gardens, from a mare by a hybrid 



16 Floarens, ' Longevity Humaine,' ass-zebra, closely resembled its mother 



p. 144, on crossed jackals. With in its tail. 



respect to the difference between the 17 Mr. Hewitt, who has had such 

 mule and the hinny, I am aware that great experience in raising these 

 this has generally been attributed to hybrids, says (' Poultry Book,' by 

 the sire and dam transmitting their Mr. Tegetmeier, 1866, pp. 165-167) 

 characters differently ; but Colin, that in all, the head was destitute of 

 who has given in his 'Traite Phys. wattles, comb, and ear-lappets; and 

 Comp.,' torn. ii. pp. 537-539, the all closely resembled the pheasant in 

 iullest description which I have met the shape of the tail and general con- 

 with of these reciprocal hybrids, is tour of the body. These hybrids 

 strongly of opinion that the ass pre- were raised from hens of several 

 ponderates in both crosses, but in an breeds by a cock-pheasant ; but 

 unequal degree. This is likewise the another hybrid, described by Mr. 

 conclusion of Flourens, and of Bech- Hewitt, was raised from a hen- 

 stein in his ' Naturgeschichte Deutsch- pheasant, by a silver-laced Bantam 

 lands,' b. i. s. 294. The tail of the cock, and this possessed a rudimeuta] 

 hinny is much more like that of the comb and wattles. 

 horse than is the tail of the mule, 



