observations of Cyclojpea in the Human Subject, etc. 273 



of the snout, and gradually increased in size as it passed 

 backwards. 



In this was a peculiar septum, which also increased in 

 both size and complexity as it passed backwards. It was 

 composed almost entirely of mucous membrane, and was 

 somewhat T shaped ; the vertical limb was continuous with 

 the floor of the cavity, and the two lateral limbs were so 

 folded downwards that they appeared almost like the mem- 

 brane covering the turbinated bones. The canal, after 

 increasing in size, passed to the base of the " trunk," where 

 it terminated in a blind bony extremity. 



On making a transverse section through the eyeball about 

 midway between its anterior and posterior extremities, the 

 sclerotic and choroid coats could be made out with perfect 

 distinctness, but there was not the slightest trace of a retina 

 or nervous elements. 



The cavity was filled with a reddish brown coagulum, 

 which appeared to be blood. On examining the posterior 

 aspect of the anterior section of the eye, no trace of the 

 partial division observed from without could be seen. The 

 globe was perfectly simple, and had no septum of any kind. 

 Nothing could be found to represent a lens. A single pig- 

 mented band surrounding the pupil very irregularly was all 

 that was to be seen of an iris. When first seen the cornea 

 was quite transparent. In the posterior half, as mentioned 

 above, there is no retina. 



The alterations in the bones of the skull were very similar 

 to those of the human foetus already described. The two 

 lateral portions of the pre-sphenoid had united in the middle 

 line, leaving a small foramen, which apparently represented 

 the optic foramen. It was occupied simply by fibrous tissue, 

 in which there were no nervous strands, the optic nerve 

 being quite absent. Immediately around the anterior or 

 orbital aspect of this foramen the bone afforded attachment 

 to a number of muscular fibres — the muscles of the eyeball. 

 The two sphenoidal fissures were of large size. The body of 

 the post-sphenoid was firmly ossified to the great wings, and 

 the whole of these parts were smaller than normal. The 

 two temporal bones were somewhat irregular in shape, and 



VOL. IX. s 



