The American journal of the medical sciences (1827)
[Thorofare, N.J., etc.] Charles B. Slack [etc.] · leaf 375
g only a membranous connection above and a semi-cartilaginous one below. This is a provision of nature to diminish the vertical and biparietal diameters of the head during the process of labour: for in every labour the "occipital portion always slides beneath the parietal, however slightly the head…
Medicine
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.