482 SECTIONAL TRANSACTIONS.—I, J. 
(Lasoratory DEMONSTRATIONS.) 
25 Dr. F. A. Dourrienp.—Demonstration of the Method used for 
the Measurement of the Cost of Cycling at Varied Rates and 
Work. 
26. Prof. Cuartes E. Wanker and Miss F. M. Tozer.—Cytological 
Demonstration. 
27. Prof. W. Ramspen.—<Adsorption Films. 
28. Mr. R. Watson Jones.—The Metabolism of the Frog at Different 
Temperatures. 
Two series of six-hourly experiments were conducted with frogs, at tempera- 
tures varying between zero and 35° C., using a slightly modified Haldane- 
Pembrey apparatus. The CO:z production was estimated, and found not to 
increase regularly with every rise of temperature, it being quite constant 
between 15° and 20° C. This confirms some experiments by Pembrey, where 
the range of temperature was 9° to 19° C. 
At temperatures which are normal for the frog—0° to 20° C.—the animal 
has some control over its metabolism, so that the increased CO: output, 
associated with a unit rise of temperature, becomes smaller as the temperature 
is raised. Between 20° and 35° C. (abnormal temperatures for the frog) there 
is no control, and the frog behaves simply as a chemical mass, the CO2 output 
increasing two or three times for every 10° C. rise of temperature. 
The CO, production in frogs at 37° C. is—per kilogram of body weight—the 
same aS In a resting man. 
SECTION J.—PSYCHOLOGY. 
(For references to the publication elsewhere of communications entered in 
the following list of transactions, see p. 506.) 
Thursday, September 13. 
1, Prof. T. H. Pear.—Imagery and Mentality. 
Importance of realising that the thinking processes in different persons may — 
employ different vehicles and proceed along different routes. The importance 
of various kinds of imagery and of imageless thought in the mental life of the 
individual. Abilities and disabilities accompanying the predominance in an 
individual of a particular kind of imagery. The influence upon psychology 
itself of writers whose mentality is strongly coloured by a certain imagery type. 
2. Joint Discussion with Section F on The Inter-connections 
between Hconomics and Psychology in Industry. 
3. Joint Discussion with Section G on Vocational Tests for Engi- 
neering Trades. i 
The importance of vocational tests in the selection of employees, and in — 
the guidance of juveniles to future careers. 
The general principles of selection. General intelligence, specific abilities, 
temperament and physique as factors in the choice of workmen. The difficulties 
of vocational testing in the engineering trades owing to the variety of types 
of work, and the different types of machine used. The four general methods of 
arriving at the type of vocational tests. Vocational testing in engineering on 
the Continent and in America. The use of group tests and individual tests in 
vocational selection. Analysis of engineering trades according to specific abili- 
ties and temperamental factors required. How such an analysis may be arrived 
