1884.] On the Human Lachrymal Bone and its Ossicles. 447 



March 27, 1884. 



THE PRESIDENT in the Chair.] 



The Presents received were laid on the table, and thanks ordered 

 for them. 



The following Papers were read : — 



I. "Notes on the Varieties and Morphology of the Human 

 Lachrymal Bone and its accessory Ossicles." By A. Mac- 

 ALISTER, F.R.S., Professor of Anatomy in the University 

 of Cambridge. Received March 14, 1884. 



(Abstract.) 



The author has examined 1000 lachrymal bones and the soft ports 

 of over 300 orbits, and has deduced therefrom notes on the following 

 points : — 



I. Cases of absence of the lachrymal bone. 



II. Rudimentary conditions : — 



a. Development of an orbital plate only. 

 ft. Division into two detached ossicles. 

 7. Development of a crest only. 

 B. Fenestration. 



e. Presence of marginal fontanelles. 



III. Varieties in outline, suturation, and frequency of ankylosis. 



IV. Varieties of crista: — 



A. Simple lamellar forms with no crest. 



B. Simple carinate forms. 



C. Carino-acuminate forms. 



D. Carino-hamate. 



V. Measurements of the bone in adult male and female, and the 

 deduction of lachrymal index - X ^^ - 



VI. The vascular relations of the bone, which are shown to be 

 almost exclusively with the infra-orbital artery, not with the angular. 



VII. The disposition of the periosteum and soft parts, and the 

 relation thereto of the tendo oculi and muscles, as well as the 

 relations of the bone to the neighbouring cavities in the ethmoid. 



