Chap. XIV. 



PPEPOTENCY OF TRANSMISSION. 



67 



with trumpeters for three generations, by which time the mongrels had 

 7-8ths of this blood in their veins, yet the tuft over the beak did not 

 appear. At the fourth generation the tuft appeared, but the birds thou-h 

 now having 15-16ths trumpeter's blood, still did not trumpet. This ca & se 

 well shows the wide difference between inheritance and . prepotency ■ for 

 here we have a well-established old race which transmits its characters 

 faithfully but which, when crossed with any other race, has the feeblest 

 power of transmitting its two chief characteristic qualities 



I will ghe one other instance with fowls and pigeons 'of weakness and 

 HJ f the transmission of the same character to their crossed offspring 

 The Silk-fowl breeds true, and there is reason to believe is a very ancient 

 race; but when I reared a large number of mongrels from a Silk-hen bv a 

 Spanish cock, not one exhibited even a trace of the so-called silkiness Mr 

 Hewi also asserts that in no instance are the silky feathers transmitted 

 by this breed when crossed with any other variety. But three birds out 

 of many raised by Mr. Orton from a cross between a silk-cock and a ban- 

 tam-hen had silky feathers.- So that it is certain that this breed very 

 mS^v llasthe P^ of transmitting its peculiar plumage to its crossed 



Sn\h£h fT ^ Dd '. there iS a Sllk s * b -™™ty of the fantail 

 pigeon, which has its feathers m nearly the same state as in the Silk-fowl ■ 



wpIw ? ady SGen that fantail8 ' Wlien crossed > P^ess singularly 



weak power m transmitting their general qualities; but the silk sub- 



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

 wrth races and indmduala Gartner has nneqnivocauy shown" Zat thi 



ZTLTZTt plants - To r one insW: wta *-«™ i« c - 



* ^ th, p^Xu^T^r^^ tl 



I fZt 1 tha * the P re P° ten <=y of one species over another in transmission 

 witn wnich the one fertilises the other 



^l^Z'Lt: JaCkal " PreP ° tent ° Ver the **' as is ^ated by 



5to^ti ca^>r^,TT bGtWeen thGSe animal8 ' and this was 

 Z er I canTot iL* ^ brid whicl > 1 °«* »w between a jackal and 

 the ass is Tle't n ' 7 ^ ° bservatio » s of Colin and others, that 

 rnmZmaSSSvT ! i^ 5 *" P re P ote ^ * this insknce 



that hf Sue Sl ;r g the male tiian throu ^ the femaie ■»; » 



mule resembles the ass more closely than does the hinny " the 



' Physiology of Breeding,' p 22 • 

 Mr. Hewitt, in ' The Poultry Book ' bv 

 Tegetmeier, 1866, p. 224. 



14 Boitard and Corbie, ' Les Pio-eons ' 

 1824, p. 226. ° ' 



lo ' Bastarderzeugung," s. 256, 290 

 &c. Naudin (< Nouvelles Archives du 



Museum,' torn. i. p. 149) gives a striking 

 instance of prepotency in Datura stramo- 

 nium when crossed with two other 

 species. 



16 Flourens, ' Longevite Humaine,' 

 P- 144, on crossed jackals. With 

 respect to the difference between the 

 F 2 



