214 WHEAT PRODUCTION IN NEW ZEALAND 
farmers have attained such a high standard, their 
efficiency in organisation must be regarded as relatively 
high. 
(d) General Lay-out of Farms—A question of organ- 
isation connected closely with the problem of combining 
a good rotation of crops with efficient methods of culti- 
vation, arises from the problem of ‘‘laying out’’ the 
farm in such a manner as to obtain the maximum of 
efficiency in production. Under this particular line of 
investigation a consideration of the whole question of 
mixed farming is strictly relevant, as well as a general 
discussion on matters such as the most convenient size 
and shape of fields, the relative position of the fields, the 
site of the homestead, implement sheds, stables, grain 
stores, etc., the provision of an adequate water supply 
and the whole question of irrigation or distribution. 
In pursuing any one line of action, the farmer is 
guided by the consideration of the relative degrees of 
profit which the various pursuits offer. Consciously or 
otherwise, it is this principle of ‘‘substituting’’ a higher 
profit for a lower one, of so distributing his energy that 
he obtains equi-marginal returns, that guides the farmer 
in his choice of occupation. The recent transition from 
agriculture to pastoral farming affords certain phe- 
nomena undoubtedly confirmatory of the economic law 
of substitution. Irrespective of what reasons farmers 
offer for their change in attitude towards agriculture, 
there still remains the fact that the predominant motive 
in the economic world is that of self-interest, widely 
interpreted. Individuals pursue that line of occupation 
which offers the greatest relative advantages, and 
obviously farmers would not be partially giving up 
wheat growing, were it not for the fact that pastoral 
farming still affords a relatively higher profit. 
But New Zealand of comparatively recent years has 
developed a great industry, the inception of which 
