A CASE OF CYCLOPIA 



197 



and to the inner side of the external canthi. The remainder of 

 the inferior margin of the orbit for the short distance medial to 

 the tubercles representing the lower lids is formed on either side 

 by the palatine processes of the maxillary elements. Owing to 

 a condition of hare lip and partial cleft palate, a boundary in 

 the mid-line ventrally is lacking between the mouth cavity and 

 the conjunctival sac above. 



It thus happens that the mucous membrane lining the roof 

 of the mouth becomes continuous with that lining the conjunc- 

 tival sac, around the margins of the cleft palate (fig. 2). The 



s.c. 



Fig. 2 Schematic coronal section through face region, showing relations of 

 oral cavity and conjunctival sac. B.O., bulbus oculi; CO., oral cavity; O.C., 

 ocular conjunctiva, continuous with the parietal layer (P.C), at the fornix con- 

 junctivae (F), which is indicated in dotted lines as being on a deeper plane; O.M., 

 oral mucosa which becomes continuous with the parietal layer of the conjunctiva 

 (P.C), through the cleft (X) between the maxillary elements (Max). 



Fig. 3 Diagram of anterior surface of bulbus. F., fornix conjuntivae indicated 

 in dotted lines; P., pupil; S.C, sclero-corneal junction; x., small pigmented area 

 at margin of cornea. 



condition of cleft palate ceases about 3 cm. from the red margin 

 of the upper lip. In the median line at the point of closure of 

 the palatine cleft the parietal layer of the conjunctiva becomes 

 reflected on to the eyeball. On both sides lateral to this point 

 of attachment, the conjunctival sac extends for some distance 

 backward before the inferior fornix is reached. A similar con- 

 dition obtains above, the two lateral pouches being separated 

 from one another in the mid line dorsally at the notch situated at 

 the base of the proboscis. These relations will be made clear 

 by reference to the diagram (fig. 3), where the line of reflection 

 of the bulbar conjunctiva is indicated in dotted lines. 



THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 23, NO. 3 



