to the great importance of the subject, which, however, it must 

 be remarked, is still in its infancy, the human maps of these 

 investigators are reproduced here as Figs. 3, 4, 5, and 6. 



As might be expected in the case of such elaborate and totally 

 independent investigations, and in view of the great difficulties 

 involved in the cutting up, blocking, sectioning, orientating, and 

 reproducing in diagram form of the cortex of entire human hemi- 

 splieres, the maps given by Brodmann and by Campbell differ 

 considerably in detail from one another. 



They agree with one another, on the other hand, much more 

 than either of them resembles the maps of Flechsig (see Fig. 2). 

 It must not be forgotten, however, that the diagrams of Flechsig 

 indicate the projection areas of the foetus, which there is reason 

 to suppose differ considerably in distribution from those existing 

 in the adult. This difference is due to the increased development 

 of the later evolved associational spheres in the latter, which 

 affects both the position and the relative size of the earlier evolved 

 projection spheres. For example, Flechsig's area for bodily sensi- 

 bility is both pre- and post-Rolandic, although he states that the 

 majority of the projection fibres pass behind the central fissure. 

 In the adult it is at least probable that this projection area is 

 entirely post-Rolandic ; and it is known that the psychomotor 

 area is pre-Rolandic. At the period when the latter area was 

 considered to be both pre- and post-Rolandic, and to be sensori- 

 motor in function, its supposed distribution closely resembled the 

 foetal bodily sensibility area of Flechsig ; and the two were re- 

 garded as identical. The maps of Brodmann and of Campbell 

 must not therefore be regarded as impugning the general accuracy 

 of the diagrams of Flechsig with regard to the projection areas of 

 the foetus. 



It may be remarked that in only two regions are the maps of 

 Brodmann and of Campbell in complete accord, namely, in the 

 psychomotor or Betz cell area (4 of Brodmann and " precentral " 

 of Campbell), and the visuo-sensory area (17 of Brodmann 

 and " visuo-sensory " of Campbell). The former of these is the 

 area mapped out by Lewis and Clarke (1878), and the latter is 

 that mapped out by the writer (1900). The extent of the visuo- 

 psychic region (18 of Brodmann), which was described by the 

 present writer as surrounding the visuo-sensory area, but was not 

 more closely defined owing to its somewhat indefinite limits, 



