228 Professor Clark on a Case 



of convolutions. Neither is there any sulcus on the upper surface 

 of that side of the brains which corresponds to the less perfect 

 face. On the corresponding surface of the other, however, is a 

 deep oblique fissure, as though the anterior lobes of these oppos- 

 ing hemispheres had not united throughout. The ventricles on 

 either side form a common cavity. 



The crura cerebri of the opposite brains are melted together 

 over the oval aperture of the united sphenoid bones. From this 

 point the tubera annularia diverge separately : and are connected 

 to well formed, distinct cerebella. The medullae oblongata? and 

 spinales proceed from them naturally. 



There is no vestige of any olfactory nerve. The optic nerves 

 are very small. The right optic tractus, of one foetus, converges 

 to its ingrassial bone; at which point it meets the left optic tractus 

 of the other foetus. Here the two unite to form a single optic 

 nerve for either face. 



There is nothing remarkable in the other nerves. They have 

 their usual apparent origins, and their usual passages through the 

 cranial bones. The left vagi send a recurrent nerve round the 

 aortas : the right do not surround any artery. They appear to 

 waste themselves almost entirely in forming the pulmonary and 

 cardiac plexus, and thus connect the separate sympathetic systems 

 in the neck and thorax. 



Dimensions supposing the more perfect face to look forward : 

 Right Foetus. Left Foetus. 



Total length from vertex to heel 14.5 inches 13. 9 inches. 



From vertex to common umbilicus... 6.0 



Shoulder point to shoulder point 3.5 3.2 



Shoulder point to end of fingers 6.0 6.0 



Round the elbow 2.5 2.3 



Length of foot 2.0 1.8 



