40 Effie A. Eead 



nected with the palate, and this was divided in the median suture. The 

 most successful dissection of this organ in those cases was obtained by 

 sawing the entire head in two from front to back, including both the nose 

 and the brain; the entire septum being on one side. The cartilage and 

 the bone were then removed from the mucosa. The vomeronasal organ 

 was found as an elongated flattened fold at the cephalic end of the 

 nose, just above the palate (Figs. 2, 4, 8, 9). Its small cephalic end 

 passes ventrad to the incisors and opens into the ductus naso-palatinus, 

 which leads from the oral to the nasal cavity. In man the position of 

 this organ is somewhat difi^erent (Fig. 21). It is found some distance 

 above the palate and not in intimate relation with it as in the dog and 

 the cat. It opens directly into the nasal cavity. The vomeronasal 

 cartilage is represented by only a small piece of cartilage which lies 

 some distance ventrad of the organ and not enclosing it as in the lower 

 animals (Fig. 21). 



I wish to emphasize what has been stated before. It is the deepest 

 layers of the mucosa next to the bone and not the nasal side with which 

 we are at present concerned. There are many nerves in this septal 

 mucosa. These nerves are from two distinct sources : the olfactory 

 nerves, which are connected with the olfactory cells and which can be 

 seen to pass through the foramina of the cribriform plate, and the 

 anterior ethmoidal and spheno-palatine branch of the 5th nerve. The 

 olfactory nerves are found near the cribriform plate (Figs. 2, 4, 7, 9) ; 

 the branches of the 5th nerve innervate the middle and cephalic parts of 

 •the nose (Figs. 2, 4, 7). 



There are still several prominent nerves which we have not described 

 (Figs. 2, 4, 8, 9). These are olfactory nerves. They were traced from 

 the olfactory bulb obliquely across the septal mucosa into the vomero- 

 nasal organ. In the dog, the cat and man they branch many times just 

 before their distribution in this organ. The vomeronasal organ in dog 

 and cat is also innervated by several branches from the naso-palatins 

 nerve; thus we see that this organ contains nerves from two distinct 

 sources. In man, according to von Kolliker, these olfactory nerves are 

 present only up to the third month of development and atrophy directly 

 after that. Mihalkovics did not find them at all in a threa months 

 human fetus. Long olfactory nerves resembling in every way those of 

 the dog and the cat were seen on the septum of a child. These were 

 traced to the vomeronasal organ. The naso-palatine branches were 

 traced nearly to this organ, but the nerve was so fine that further 

 dissection was not successful. 



