430 SECTIONAL TRANSACTIONS.— M. 



higher wage. We must aim at larger and faster teams and bigger implements, and 

 we must substitute, as far as possible, the work of the horse or the tractor for that of 

 the man. 



3. Discussion on Soil Classification. 



Mr. G. W. Robinson, Prof. J. Hendrick, Mr. L. F. Newman, 

 Mr. C. G. T. MoRisoN, Mr. W. Morley Davies. 



4. Joint Meeting with Section L (q.v.) on Educational Training for 



Overseas Life. 



Friday, August 6. 



5. Discussion on Agricultural Education. 



Mr. H. E. Dale, C.B., Prof. T. B. Wood, F.R.S., Mr. W. A. Stewart, 

 Mr. J. Duncan. 



6. Mr. R. G. Hatton. — Rootstock Investigations on Apples and. Plums 



7. Dr. E. J. Collins. — The Physiological Aspect of Potato Blight. 



(Taken as read.) 



The physiological condition of the foliage of early, mid-season, lat*, and very late 

 varieties of potatoes was determined at intervals throughout the season by making the 

 following determinations. Leaf area was used as the basis of calculation where 

 desirable. 



1. The water content of young, medium, and old foliage. 



2. The nitrogen content of the same, together with 



3. The water to nitrogen ratio. 



4. The diurnal variation of these data, and 



5. The effect of spraying on these data. 



A record of the meteorological conditions was kept. 



Consistent results have been obtained over a period of six years. 



The conclusion is reached that high yield and high resistance to late blight, represent 

 the expression of the two extreme values of the same physiological complex, hence it is 

 not anticipated that a variety combining the two characteristics will be produced. 

 On the other hand, immunity, combined with high yield, may be obtained by the 

 discovery of some new form or variety which possesses a definite immunity factor 

 segregating independently of the physiological complex which, in the material at present 

 available, determines maturation, susceptibility, and yield. 



8. Exhibits at the School of Rural Economy and Institute for Research 



in Agricultural Economics. 



Saturday, August 7. 



Excursion to Reading, visiting Messrs. Sutton's seed establishment 

 and the Agricultural Department, Reading University, and the National 

 Institute for Research in Dairying, Shinfield. 



Monday, August 9. 



9. Presidential Address by Sir Daniel Hall, K.C.B., F.R.S., on 



The Relation between Cultivated Area and Population, at 

 Joint Meeting with Section F {q.v.) to discuss The Limits of 

 Agricultural Expansion. (For Address, see p. 255.) 



