October 30, 1003.] 



SCIENCE. 



547 



of the skill], and have paid eompai-atively 

 little attentiou to the form of the cranial 

 cavity. The onter surface of the cranium 

 presents features which are due to other 

 factors than brain development, and ex- 

 amination of the cranial cavity not only 

 gives us important information as to brain 

 form, but by affording a comparison be- 

 tween the external and internal surfaces of 

 the cranial wall it gives a valuable clue to 

 the real significance of the external config- 

 uration. Beyond determining its capacity 

 we can do but little towards an exact in- 

 vestigation of the cranial cavity without 

 making a section of the skull. Forty years 

 ago Professor Huxley, in his work 'On 

 the Evidence of Man's Place in Nature,' 

 showed the importance of a comparison of 

 the basal with the vaulted portion of the 

 skull, and maintained that until it should 

 become 'an opprobrium to an ethnological 

 collection to possess a single ski;ll which 

 is not bisected longitudinally' there would 

 be 'no safe basis for that ethnological 

 eraniology which aspires to give the an- 

 atomical characters of the crania of the 

 different races of mankind.' Professor 

 Cleland and Sir William Turner have also 

 insisted upon this method of examination, 

 and only two years ago Professor D. J. 

 Cunningham, in his presidential address to 

 this section, quoted, with approval, the 

 forcible language of Huxley. The curators 

 of craniological collections appear, how- 

 ever, to possess an invincible objection to 

 any such treatment of the specimens under 

 their care. Even in the Hunterian ]\Iu- 

 seum in London, where Huxley himself 

 worked at this subject, among several thou- 

 sands of skulls, scarcely any have been bi- 

 sected longitudinally, or had the cranial 

 cavity exposed by a section in any other 

 direction. The method advocated so 

 strongly by Huxley is not only essential to 

 a thorough study of the relations of basi- 



cranial axis to the vault of the cranium 

 and to the facial portion of the skull, but 

 also permits of casts being taken of the 

 cranial cavity ; a procedure which, I would 

 venture to suggest, has been too much 

 neglected by craniologists. 



Every student of anatomy is familiar 

 with the finger-like depressions on the 

 inner surface of the cranial wall, which 

 ai-e described as the impress of the cerebral 

 convolutions; but their exact distribution 

 and the degree to which they are developed 

 according to age, sex, race, etc., still remain 

 to be definitel}' determined. Indeed, there 

 appears to be a considerable difference of 

 opinion as to the degree of approximation 

 of the outer surface of the brain to the 

 inner surface of the cranial wall. Thus 

 the brain is frequently described as lying 

 upon a water-bed, or as swimming in the 

 cerebro-spinal fluid, while Hyrtle speaks 

 of this fluid as a 'ligamentum suspenso- 

 rium ' for the brain. Such descriptions are 

 misleading when applied to the relation of 

 the cerebral convolutions to the skull. 

 There are, it is true, certain parts of the 

 brain which are surrounded and separated 

 from the skull by a considerable amount of 

 fluid. These, however, are mainly the 

 lower portions, such as the medulla ob- 

 longata and pons Varolii, which may be 

 regarded as prolongations of the spinal 

 cord into the cranial cavity. As they con- 

 tain the centers controlling the action of 

 the circulatory and respiratory organs, they 

 are the most vital parts of the central nerv- 

 ous system, and hence need special protec- 

 tion. They are not, however, concerned 

 with the regulation of complicated volun- 

 tary movements, the reception and storage 

 of sensory impressions from lower centers, 

 and the activity of the various mental proc- 

 es.ses. These functions we must associate 

 with the higher parts of the brain, and 



