38 Effie A. Eead 



pass to the olfactory folds (Fig. 3), and to the lateral wall and septum 

 (Figs. 1-4). It would, therefore, seem probable that the nerves de- 

 scribed above are the free terminations of the 5th nerve. My prepara- 

 tions agree very closely in appearance with those of Eetzius for the 

 mouse and cat. I find no structure in the nasal epithelium of dog, cat 

 or man which resembles the "Geruchsknospen" of Blaue or the "Epithel- 

 knospen" described by Disse. 



Organon Vomeronasale. 



This organ has been the subject of various investigations; a detailed 

 account is given by Kolliker, 1877, 1883, and Harvey, 1883 ; von Brunn, 

 1892; von Lenhossek, 1893; Merkel, 1893; Mihalkovics, 1898. Klein 

 worked on the guinea pig, the rabbit and the dog; von Lenhossek on 

 the rabbit ; Harvey on the mouse and the cat ; von Brunn on the sheep ; 

 Kolliker, Merkel and Mihalkovics on man. 



The gross structure, briefly stated, is as follows : 



The vomeronasal organ of the dog and the cat is a bilateral tubular 

 organ situated in the ventral part of the septum in the region of the 

 pre-maxillary and maxillary bones. It is either entirely or partially 

 surrounded by a capsule of hyaline cartilage (Figs. 15, 18, 54, 55). At 

 the cephalic end of the nose there are two prominent folds on each side 

 of the nasal septum. The dorsal one is due to a solid fold of the 

 mucosa and to the presence of glands. This is the smaller and passes 

 dorsad of the incisors. The cartilaginous capsule is complete in the 

 cephalic part of the vomeronasal organ of the cat. In the remaining 

 portion in the cat and through its entire extent in the dog this capsule 

 is only partial. As stated above, the vomeronasal organ is tubular and 

 is flattened laterally. It is blind at the caudal end, but opens at the 

 cephalic end into the ductus nasopalatinus. In man the vomeronasal 

 organ is much less developed than in dog and cat. It is a bilateral organ 

 situated in the mucous membrane of the ventral part of the nasal 

 septum (Fig. 31). It is a short blind tube only a few millimeters in 

 length which opens anteriorly into the nasal cavity by a small pore-like 

 opening just above the incisors. This opening was seen both in child 

 and adult. The cartilage of this organ is much reduced and lies entirely 

 below the organ (Fig. 21). The shape of the tube in the dog and the 

 cat varies in the different regions ; near the cephalic opening it is 

 circular in transection and lined with stratified epithelium; in the 



