274. REPORTS ON THE STATE OF SCIENCE, ETC. 



arranging the parts to be assembled, (ii) the determination of the best order in which 

 to assemble the parts, (iii) the elimination of needless movements, (iv) the avoidance 

 of awkward movements, (v) the determination of ' accident ' points, i.e. points at 

 which it is imperative to ' slow down ' if error is to be avoided, and (vi) instruction in 

 the principles involved in the foregoing points. 



F. Work in Progeess. 

 Work in progress includes — 



(1) An examination of the relation between the abilities measured in the one 

 group of ' backward ' school girls. 



( 2 ) An analysis of the processes involved in ' intelligent ' and in ' routine ' assembling . 



G. Further Work Suggested. 



The results so far obtained suggest further work in the direction of — 



(i) Investigating the relation between the most complex assembling operations and 



the simpler ' motor ' tests, such as those referred to in the Report on Manual 



Dexterity recently issued b}^ the National Institute of Industrial Psychology. 



(ii) Investigating the effect of training, as suggested in E.VI (6), on the ultimate 



ranking of a group of subjects previously graded by assembly tests. 

 The Committee ask for a renewal of the grant. 



September 1930. 



Mycorrhiza in Relation to Forestry,—Report of Committee (Mr. 

 F. T. Brooks, Chairman ; Dr. M. C. Eayner, Secretary ; Dr. H. M. 

 Steven). Drawn up by the Secretary. 



The grant was asked for as a contribution towards expenditure incurred in : 



A. The collection of data and material from forestry stations in various parts of 

 the British Isles. 



B. The planning and starting of field experiments in a selected area, supplemented 

 and extended by pot cultures and laboratory observations and experiments. 



It must be understood that any scheme of research likely to jdeld results of value 

 in this subject must be planned to cover a period of several years, for which reason 

 the present report necessarily takes the form of a general account of the scheme of 

 work with details of those parts of it actually under way, rather than a description of j 

 results already achieved. 



The main purposes of the research may be summarised as follows : — 



(1) To ascertain whether the formation of normal mycorrhiza may fairly bej 

 regarded as a causative factor in the healthy growth of young trees. It may bej 

 assumed as already established that it is an invariable concomitant of such growth. 



(2) To determine whether the absence of mycorrhiza associated with unsatisfactory! 

 growth is related to : — 



(a) absence of the mycorrhiza-forming fungi appropriate to the trees ; or, 



(b) the existence of soil conditions inimical to the formation of functional! 

 mycorrhiza of a type beneficial to the trees. I 



(3) To ascertain whether it is practicable to supply deficiencies or ameliorate 

 existing soil conditions by experimental treatment of nurserj- stock or in other ways. 



At this stage the enquiry has been limited to members of the genus Finns in 

 common use for afforestation in Great Britain and the Dominions ; in particular, 

 Corsican Pine (P. laricio), Maritime Pine (P. pinaster) and P. contorta, with co- 

 ordinated observations on Scots Pine (P. silvesiris) and Mountain Pine (P. uncinata). 

 In the three species first named, no data are at present available with respect to the 

 structural types of mycorrhiza normal to the trees in their natural habitats, or the 

 fungi responsible for its appearance in each case. Incidentally, the formation of a 

 type collection of mycorrhizas from the native habitats of these and other species of 

 Pinus for purposes of reference is urgently required as a preliminary step in research 

 on the subject, and would undoubtedly be of practical service to foresters both in 

 this country and the Dominions. 



The work carried out since allocation of the grant is as follows : — 

 (A) Visits have been made to a number of forestry stations and experimental plots 

 in Great Britain and Ireland, and comparative observations made and filed on the 

 types of mycorrhiza formed by species of Pinus under various soil conditions. 



