414 SECTIONAL TRANSACTIONS.— TEXTILES. 



Friday, September 2. 



Visit to the Department of Textile Industries, University of Leeds. 

 Papers : — 



Dr. F. W. Dry. — Mendelian Breeding with Wensleydale Sheep. (Preceded 



by exhibition of sheep illustrative of the paper.) 



The main features in colour inheritance in the Wensleydale breed of sheep follow 

 simple Mendelian lines. The occurrence of black lambs in white flocks therefore 

 offers a favourable opportunity for applying Mendelism to a breeding problem in a 

 large domestic animal. The successive steps in this undertaking are described, and 

 certain practical considerations discussed. An attempt is now being made by the 

 University of Leeds to build up a flock of pure whites. 



Prof. A. F. Barker. — Race and Environment as affecting the Type of Sheep 

 and the Wool Supplies of the World. 



Three fairly distinct lines of adjustment of race to environment may still be noted 

 in making a survey of the sheep of the world. The first line is the most natural, that 

 in which man has played no part, Nature only having taken the adjustment in hand. 

 In the second line of adjustment, man has accidentally or incidentally interfered with 

 Nature, but has consciously taken no part in deciding the line of evolution. In the 

 third line, man has consciously and deliberately adjusted the race of sheep to the 

 environment, and in some few cases has actually created the environment necessary 

 for the evolution of a required type of animal. 



If extent of distribution is some sort of a measure of the antiquity of a given type, 1 

 then it may be taken that the wild double-coated sheep of the Moufflon-Urial type is 

 our primitive sheep, having representatives, more or- less adjusted to the environment, 

 in Asia, Europe and America. 



It is, however, exceedingly difficult to find any large number of sheep in a perfectly 

 open country which have not been interfered with by man — even the Soay and the 

 Shetland sheep, although very near to the wild type, show traces of such interference. 

 But the best example of the second line of adjustment is that now in evidence in 

 Peru. The Spanish merino and the Spanish Park sheep (piebald) have there been intro- 

 duced, as incidental to conquest, and for hundreds of years have been adjusting 

 themselves to the table-lands some 12,000 to 14,000 feet up the Andes, with character- 

 istic results which the wool manufacturer knows how to utilise in the production of 

 his fabrics. 



The third line of adjustment is practically in evidence in every wool-producing 

 country in the world : New South Wales may be selected as a typical example. 

 Here four zones, from the coast to the plains beyond the Blue Mountains, are to be 

 noted, and for each of these zones the sheep-breeder has evolved a particular type of 

 sheep yielding the best return possible in wool and mutton. 



The conditions under which the several types of sheep have been reared are still 

 reflected in the ' make-up ' of particular breeds. Thus, the merino, accustomed to 

 * follow-my-leader ' in the narrow valleys of Spain, still retains this character and 

 often will not spread out over quite open pasture lands ; while the English sheep — 

 probably descended from a sheep brought across the central plain of Europe by 

 nomadic tribes — naturally spreads out and forages to advantage. Merino ewes when 

 grouped together hold their heads down in a characteristic fashion, and may transmit 

 this peculiarity to their crossbred offspring. These and other characteristics are 

 being observed in sheep and, properly understood, may enable the sheep-breeder to 

 make the best possible adjustment of race to environment. 



The Australian, South African, and other sheep breeders, acting on the lines of 

 mass selection, have attempted to evolve the type of sheep best fitted to the 

 environments with which they have to deal and, upon the whole, have been wonder- 

 fully successful. It is now being recognised that Mendelian characters, which so far 

 have been the despair of the unscientific breeder, may now be reshuffled or readjusted, 

 frequently just on the lines desired, and thus the required type of sheep produced. 

 Type of coat, the casting of the outer hair (kemp), and retaining of the under coat 



1 Dr. Willis and Mr. G. Udny Yule on The Plants of Ceylon. 



