xlviii Journal of Comparative Neurology. 



less rather than more accurate in his estimates as a result of loss of 

 attention. It seems to the reviewer that the use of blunt divider 

 points serves to invalidate this class of experiments. It was found that 

 the unsophisticated subject often reported several impacts where there 

 was really but one. May this not be due to the fact that the pressure 

 of a blunt point affects several tactile corpuscles and to the further 

 fact that there is actually communication between corpuscles in the 

 skin providing for irradiation (cf. Dogiel) ? The proper method of ex- 

 periment might be the use of a leather shield laid upon the skin and 

 having small perforations through which the needles or pomts could be 

 passed, the pressure of the close-fitting shield being so great as to pro- 

 hibit attention to the slight pressure and flexion due to the points. In 

 this way also a proper orientation is possible. 



C. L. H. 



Influence of Mental Effort on Blood Pressure.^ 



The only satisfactory study of the variations of blood pressure in 

 man due to thought is that of Kiesow (Arch. ital. de Biol. 1895). In 

 the author's attempts to extend 'these observations Mosso's sphygmo- 

 manometer was used. It was noted that the amplitude of pulse vibra- 

 tion varies independently of the blood pressure. This fact greatly 

 complicates the method, making it necessary to supplement the record 

 of pulse tracing by a record of the actual variation at the most favor- 

 able counter pressure. The curve of pressures of the state of rest has 

 a greater amplitude than that of intellectual work. A diminution of 

 pulse due to vascular constriction may be inferred. On the other 

 hand the pulse is more resistent to higher pressures, hence there is 

 greater vascular pressure during mental effort. c. L. h. 



A Cortical Centre for Spelling.^ 



From a study of six cases of aphasia,^ details of which cannot be 

 given here, Dr. Eskridge arrives at the conclusion that an area at the 

 foot of the second frontal convolution presides over the memories of 

 the arrangement of the letters in words. The letters may be formed 

 perfectly but they are confused and jumbled together so as to be unin- 

 telligible. The areas involved were localized by operation which in 

 some cases produced a degree of relief. c. l. h. 



1 BiNET AND Vaschide." Psych. Rev. IV, i, Jan. 1897. 



'^ J. T. Eskridge. Speech Defect as a Localizing Symptom. Medical 

 News, Sept, 19th, 1897. 



