308 REPORTS ON THE STATE OF SCIENCE, ETC. 



Note to 7 (6). — Both normal and hypochromatic individuals use differences in 

 brightness as an aid to colour discrimination, therefore some method should be used 

 in which comparisons are made of lights of unequal brightness. As normal persons 

 have maxima of discrimination, at wave lengths 5850 A° and 4950 A°, and at the 

 same wave lengths differences in intensity do not cause a change in colour, therefore 

 one method of measurement would be to state the maximum mistakes at these 

 regions. A difference of over 50 A° or a range of over 100 A°, if the difference on each 

 side of a fixed wave length is measured, would indicate defective colour discrimination. 

 (See Roaf, Quart. J. Exper. Physiol. 1927, vol. 16, pp. 379-392.) The measurement 

 would correspond to a monochromatic patch as measured by Dr. Edridge-Green, if 

 the difference in brightness between different wave lengths of the same spectrum 

 could be eliminated. 



(c) All those persons with dichromic vision — i.e. who recognise only two colours 

 in the spectrum — possess a neutral region, the position and extent of which should 

 be determined. 



University Course in Experimental Psychology. — Report of 

 Committee (Dr. J. Drever, Chairman ; Dr. Mary Collins, Secretary ; 

 Mr. F. C. Bartlett, Mr. R. J. Bartlett, Prof. C. Burt, Dr. 

 Shepherd Dawson, Prof. A. E. Heath. Dr. Ll. Wynn Jones, Prof. 

 T. H. Pear) appointed to consider a first-year course in the above. 



1. It is realised that experimental courses must vary in procedure according to 

 circumstances, such as equipment of laboratory and number of students and nature 

 of the general course of study of the students. 



2. The aim of the Committee is to lay down fundamental principles which ought 

 to guide the drawing up of any experimental course. 



3. Theoretical psychology and practical psychology should go hand in hand from 

 the beginning. 



4. Lectures on experimental topics should be included in the general lectures. 



5. Sixty hours' laboratory work should represent a reasonable minimum in a first 

 year's course. 



6. The aim of the earlier experiments should be to familiarise the student with the 

 experimental method of approach in psychology, and at the same time emphasis 

 should be laid on the importance of introspection. 



7. The employment of the psycho-physical methods should come early in the 

 course. 



8. A first year's course should include laboratory work on perception, imagery 

 and association, learning and memory, imagination, the special senses, feeling and 

 reaction time, psycho-physical and statistical methods. 



Illumination of Plants. — Report of Committee (Prof. W. Neilson 

 Jones, Chairman ; Dr. E. M. Dele, Secretary ; Prof. V. H. Black- 

 man) appointed to make investigations on the effect of duration and 

 nature of illumination on growth and flowering in Arachis hypogcea 

 and Voandzeia subterranea. (Drawn up by the Secretary.) 



Experiments were carried out under my direction from July to October, 1926, some 

 at the Royal Gardens, Kew, by Miss K. Ritson, B.Sc, with the permission of the 

 Director, and others at the same time by Miss A. Westbrook, M.Sc, in the greenhouse 

 laboratory of Bedford College, by the courtesy of Prof. Neilson Jones. Additional 

 experiments are now in progress at the Royal Botanic Gardens, Regent's Park. 



Seeds of Arachis and Voandzeia were kindly supplied from West Africa by the 

 Director of Agriculture for the Gambia, and were grown successfully to the flowering 

 stage ; Pelargonium (hybrids) and other pot plants were also used. 



The plants were exposed daily for short time intervals (30 seconds to 15 minutes) 

 to the unscreened light of a Hewittic mercury vapour lamp, at distances varying from 

 2 to 8 feet. With exposures of 1 minute daily or longer, the modifications of growth 

 and structure were similar, and became progressively more marked with the longer 

 exposures. Exposures of 30 seconds daily in November appeared to give no result 



