19^:0] Proceedings of Elisha Mitchell Scientific Society 5 



Method) or by getting one to some extent fixed before practicing the 

 other (the Complete Method). Data were obtained by the study of the 

 learning of mazes by rats, of mazes by children, and of mazes by adults ; 

 then the scope was extended to include the formation of another pair 

 of perceptual-motor habits, card sorting, and further still to include a 

 pair of habits involving very little of the motor element, addition. 



The particular technique of the different experiments was inten- 

 tionally varied considerably: (a) in temporal distribution of trials; 

 (b) in stage at which shift was made from one to the other habit 

 by the Complete Method; (c) in arrangement of controls— division of 

 subject into groups; (d) in methods of scoring; (e) in incentives used, 



(f) in subjects' previous familiarity with the habits to be learned; 



(g) in their knowledge of the number and order of the habits to be 

 learned; (h) in their knowledge of the nature of the problem inves- 

 tigated. Thus, the general results found may be considered as inde- 

 pendent of particular details of technique and to be of general bearing. 



For results, it was found that in all the forms of double habit for- 

 mation studied, learning by the Complete Method was more economical 

 than learning b}^ the Alternate Method. This was indicated in the 

 different sets of experiments in terms of the different criteria of effici- 

 ency respectively applicable. They included: (a) number of trials 

 necessary to fix a habit; (b) degree of regularity in improvement ; (c) 

 average amounts of scores on individual trials; (d) rate of accelera- 

 tion of improvement. 



The complete paper will appear in an early number of The Psy- 

 chological Review. 



J. B. Bullitt — Report on Autopsies on 25 Cases of Influenza Pneu- 

 monia. 



Extensive cutaneous emphysema v^as encountered in one case. 

 Firm, fibrous pleural adhesions existed in six cases, in four of which 

 the lungs showed old scars of apparently healed tuberculosis while 

 one showed fibrinous exudate on the pleura, four of these exudates 

 being thick and shaggy. In three of these there was serous effusion ; 

 in two, purulent effusion. All cases exhibited the lobular type of 

 pneumonia. In seven there was also distinct lobar consolidation, 

 the lobular process in these being but slightly evident. Numerous 

 bronchiectatic abscesses occurred in four cases, while in four others 

 (three of them associated with labor consolidation) there was massive 



