The American Ophthalmological Society Transactions of the American Ophthalmological Society . 1876, 1877, 1878

1879 Boston Medical and Surgical Journal  
When we remember that the permanent vertebrae are the results of a secondary segmentation, there is little difficulty in believing that a portion of the skull, corresponding in extent to the cranial end of the notochord, is formed by the fusion of a number of vertebral elements ; but in front of this there is another portion of a different, or at least secondary, origin, and it is pretty evident that segments of the skull do not correspond individually to vertebra;. Information is also gained
more » ... om the nerves, as those which arise in front of the notochord have no resemblance to spinal nerves. Gegenbauer believes that at
doi:10.1056/nejm187905081001909 fatcat:6uphuhn6zvdurl7wsbih3usfyy