1902.] OLIVER — BLINDNESS FROM MALFORMATION OF SKULL. 161 



Should the prize of the centuries be denied to these intrepid 

 voyagers, however, it may be that some devoted enthusiast will be 

 moved to attempt to explore the unknown area in an expedition 

 planned on the lines of the Fram voyage, which after all promises 

 the greatest chance of success. 



In such an event it is hoped that the data secured as a result of 

 this drift-cask experiment may be found to be a contribution of 

 some value to the hydrography of the Arctic regions. 



BLINDNESS FROM CONGENITAL MALFORMATION 

 OF THE SKULL. 



(Plate XX.) 



BY CHARLES A. OLIVER, A.M., M.D. 



{Read April 5, 1902.) 



Congenital malformations of the skull assert their evil effects 

 upon the integrity of the tissues of the visual apparatus and its 

 consequent functioning in definite ways. Should the disturbing 

 factors be set into activity during intrauterine existence, while the 

 cranial bones are passing through their primary stages of develop- 

 ment, the direct effects of such disturbance will be so great that 

 not only will organic changes appear in the ocular structures, but 

 coarse associated faults will manifest themselves in the related and 

 contiguous tissues. 



The posterior portion of the cranium is proportionally the 

 largest during the early stages of development of the skull, the 

 parietal regions beginning to enlarge at about the eighth week of 

 intrauterine life, followed soon afterward by the frontal and the 

 occipital regions. 



The newly born cranium is relatively very large in comparison 

 with the rest of the body. In contrast with the facial portion it 

 exhibits a predominance of the cerebral part in proportion of seven 

 to one. The six membranous fontanelles and the fibrous septa 

 between the adjacent osseous structures continue intracranially with 

 the dura mater and extend extracranially to form the pericranium, 

 giving rise to sacs in which bony plates without diploe are situated. 

 At this period of life there are cartilaginous areas scattered through 

 the occipital bone, while the presphenoid portion of the sphenoid 



PKOC. AMER. PHILOS. SOC. XLI. 169. K. PRINTED JULY 8, 1902. 



