96 THE GROWTH OF THE BRAIN. 



England by Dr. Boyd. 1 In a recently published paper 

 by the late Dr. John Marshall 2 particularly good use 

 has been made of this material, and the presentation 

 of the facts there will best serve our purpose. Since 

 Boyd's series was made on English subjects, it is more 

 comparable than any other with the tables for the 

 growth of the body which have been already given. 

 Dr. Boyd examined the brains of 2,086 individuals, 

 presumptively sane, at the Marylebone Workhouse in 

 London. His method of observation is not completely 

 stated, but was apparently as follows : The brain was 

 exposed, the pia being left in place. By horizontal 

 sections the hemispheres were sliced away down to the 

 tentorium. The remaining portions of the hemispheres 

 were then separated from the quadrigemina. The 

 cerebellum was next separated from the stem, repre- 

 sented by the quadrigemina, pons, and the bulb. Each 

 hemisphere, the cerebellum and the stem, were weighed 

 separately. It will be seen that this method permitted 

 very complete drainage of the fluids found in the 

 brain after death, and this must be taken into account 

 when Boyd's figures are compared with the tables of 

 some other observers who omitted this precaution. 

 Dr. Marshall compiled from the records of Boyd the 

 observations which were important for his purpose, 

 and on these we must depend, since the separate 

 observations by Boyd were never published and are 

 now lost. Between the ages of 20-90 years, Marshall 

 finds 698 male cases and 552 female. In making the 

 table he divides these cases into three (horizontal) 

 groups according to age, putting together those from 

 20-40, those from 41-70, and those from 71-90 years. 

 The individuals who fall within each group of years are 



1 Boyd. Phil. Trans., 1861. 



2 Marshall, Journal of Anatomy and Physiology , 1892. 



