The Morphology of Cosraobia 405 



is probably a modified double optic commissure, since from the sides of 

 this the two pairs of Optici take their origin. The Olfactorii, which 

 arise from the under side of the hemispheres, have nothing to do with 

 this connective, and appear upon the perfect side quite as in a normal 

 individual, although upon the imperfect side they appear to be entirely 

 wanting. 



Behind the second pair the remaining cranial nerves are quite normal 

 in respect to origin, but their relation to the two apparent faces is such 

 that each face is supplied by corresponding nerves from the two brains, 

 which proceed from the sides adjacent to each face and become related 

 exactly as though they were an original pair of cranial nerves. The 

 result of this is that the two corresponding nerves that supply a given 

 face come from a very divergent origin, and in their course need to turn 

 outwards nearly at right angles from their initial course. 



In this manner the eyeballs of both faces are supplied with the associ- 

 ated cranial pairs, II, III, IV, and VI. Upon the perfect side the two 

 Optic nerves are distinct, each with its own foramen of exit, but upon 

 the imperfect side the two nerves approach each other, run in contact 

 through a single median optic foramen, and finally enter the median 

 eyeball as a single nerve. The other nerves of the orbit are distinct while 

 within the cranial cavity, but upon the imperfect side there are certain 

 abnormal relationships between them, to be described later. 



The two hypophyses have been already mentioned, but it may be 

 noted here that, unlike the two heads or the two livers, which are formed 

 each of two components, they belong wholly to the component of the side 

 upon which they are situated. Both still retain the fetal connection 

 with the pharyngeal cavity, and the two openings are plainly visible 

 in the roof of this latter cavity, appearing as two small pores, situated 

 close together, opening from a small recess and not directly from the 

 pharynx. They are almost at the exact center of the monster as in the 

 case of the oesophagus, but the two openings are placed laterally, and 

 thus each belongs to a single component. 



The eyes upon the perfect side, since they consist of A's right and B's 

 left, are related to each other as are the two eyes in a normal face, and 

 thus the orbital nerves, although proceeding from different brains, are 

 nearly normal in respect to position and relationships. The external 

 rectus muscle, with the Vlth nerve, appears upon the outer side of each 

 eyeball and the superior oblique, with its pulley and the IVth nerve, 

 is upon the inner. The ophthalmic branch of the Trigeminus crosses 



