Literary Notices. xiii 



for dull children 22.4. The curve for girls is more irregular than 

 that for boys and boys were quicker than girls throughout. The same 

 is true of the curve of the discrimination-time for red and blue. 



In these and other experiments cited there is usually a very strik- 

 ing fluctuation in the curv es at the age of 7 and another always at 

 puberty. It is also dedu ced that puberty has a greater effect on the 

 mental than on the physical aspects of man's nature. The develop- 

 ment of girls is far more seriously affected by periodic changes than 

 that of boys. In all the curves involving a time element there is a 

 marked loss in ability from 6 to 7. Between 11 and 12, just before 

 puberty, in both curves the bright and dull children act with about the 

 same rapidity, though both before and after that age the dull ones are 

 much slower than the bright ones. The child is judged dull at 13 be- 

 cause he is unable to act as quickly. 



This investigation is one of the most comprehensive and thorough 

 thus far published and the author has laid all educators, as well as the 

 psychologists, under great obligations. 



The volume contains several other papers, among which may be 

 mentioned one by Professor Scripture entitled, A Psychological Meth- 

 od of Determing the Blind-Spot, of especial importance as emphasiz- 

 the fact that psychological measurements are not necessarily purely 

 physical or physiological. As purely mental facts the phenomena of 

 consciousness may be measured by one another with an accuracy rap- 

 idly approaching that of physics. 



c. J. H. 



Functional Distribution of Motor Eoots.^ 



This is an experimental study of dogs, cats and rabbits for the 

 precise determination of the functional relations of the motor roots of 

 the spinal cord. Tables are given showing the motor reactions after 

 stimulation of the several roots and the following conclusions are 

 presented : 



I. The innervation of the limbs presents from the very begin- 

 ning of the medullary origin an evident systematization. The system- 

 atization is functional \ that is, the motor fibres that issue from the 

 medulla at a given level are distributed to synergic muscular groups, 

 and concur there in an associated movement. 



^POLiMANTi, OsvALDO. Sulla Distribuzione funzionale delle Radici motrici 

 nei Muscoli degli Arti. Ricerche sperimentali. Lo Sperimentale, XLVIII, 3, 

 1894. 



