SECTIONAL TRANSACTIONS.— M. 637 



Dr. J. E. Nichols. — Some Aspects of the Ecology of British Sheep. 



It can be demonstrated that, in spite of the disturbances caused by domestic 

 husbandry, the sheep is limited in its distribution by a series of environmental condi- 

 tions ; domestication has resulted in the development of difFerent types within the 

 species and selection has caused the establishment of more or less well-defined ' breeds.' 



The British Isles lie completely within the range of conditions for successful sheep 

 husbandry, but within the Isles great local differences in environment exist, and to 

 meet local conditions of environment and economic demand many difierent types or 

 breeds have been selected. Thus within the general sheep population the different 

 breeds have different distributions and perform difierent functions, and it would 

 seem that each particular type is associated with different environmental optima. The 

 definition of the conditions which limit the distribution of each type is being attempted. 



The position is obscured by the widespread practice of cross-breeding for com- 

 mercial purposes, but by considering only the aggregations of pure-bred flocks the 

 major considerations can be examined and the indication of the most beneficial 

 environment for a particular type or breed, or the most suitable type for a particular 

 environment, can be accompUshed. 



Two main avenues of approach to the problem are presented : the first is by the 

 study of the histories of development and spread of the breeds, in many phases of 

 which the method of trial and error was mainly used ; the second is by analysis of 

 the environment of the breeds to-day. 



The chief distinction between types which can be made is that between mountain 

 and lowland sheep ; associated with the differences in altitude are differences in 

 temperature and rainfall conditions. The primary differences cannot easily be 

 estabUshed, but broad distinctions can be made irrespective of whether the effects 

 of, e.g. climatic conditions, are direct or are indirectly manifested through their 

 effects on the nutritional supply or the methods of husbandry employed. 



An attempt has been made to dissociate the effects of one series of environmental 

 conditions from the other in the case of altitude, temperature and rainfall, and the 

 results of the analysis indicate that it is possible to define the optimum conditions 

 for successful husbandry of particular breeds, and to define the breeds suitable for 

 certain sets of conditions. The critical periods, such as service and lambing periods, 

 are found to fall within closely related limits of environment. 



Mr. A. D. Buchanan Smith. — Inbreeding in Jersey Cattle. (See p. 649.) 



Tuesday, September 11. 



Joint Discussion with Section F {q.v.) on The Incidence of Taxation 

 in Agriculture. 



Mr. D. A. E. Harkness. — The Economics of Small Farms. 



One of the most important problems in connection with the agricultural industry 

 to-day is the question of the best economic and social unit for farm production. In 

 most countries of the world the preponderance of small farms is increasing, and in 

 Great Britain there is a widespread demand that the land should be made to afford 

 a livelihood for a greater number of the population. Unfortunatel_v, comparatively 

 little information is available regarding the economic position of small farms. 



A comparison of the results of the census of production inquiries which were made 

 in 192.5 in England and Wales and in Northern Ireland shows that in the latter 

 country — which is a country of small farms — the value of the gross output per acre 

 is less than in England and Wales, where the bulk of the agricultural area is divided 

 into relatively large-sized farms. A greater proportion of the agricultural output 

 of Northern Ireland is, however, comprised of live stock and live stock products than 

 is the case in England and Wales. Owing to the small proportion of the crops sold 

 off farms in Northern Ireland the value of the outjjut per acre is depressed. 



After deducting rent, wages of hired labourers and rates on agricultural land from 

 the value of the net output of the agricultural industry in Northern Ireland a surplus 

 averaging slightly over £3 per acre was available in 1925 to remimerate the farmer 



