VOMERO-NASAL ORGAN 99 



length. The vomero-nasal organ of these forms has com- 

 monly associated with it a considerable amount of caver- 

 nous tissue. This tissue, which was long ago identified 

 in nasal organs by Klein (1881a, 1881b), is so disposed 

 that in connection with the surrounding cartillage and 

 other parts, it may serve as a means of changing in no 

 small degree the volume of the organ. 



5. Function. Concerning the function of the vomero- 

 nasal organ almost nothing is known. Von Mihalkovics 

 (1898) found that after burning out the naso-palatine 

 duct and more or less of the vomero-nasal organ 

 in the cat and in the rabbit, the appropriation of food 

 by these animals was not interfered with, but it is hardly 

 to be expected that so crude an experiment as this would 

 yield significant results. Kolliker emphasized the fact 

 that, at least in mammals, the connection between the 

 vomero-nasal organ and the exterior is so narrow and 

 indirect that it seems almost impossible that there should 

 be any transfer of material from the exterior to the inte- 

 rior of the organ as, for instance, is implied in olfaction. 

 He, therefore, suggested that the vomero-nasal organ 

 was concerned with testing the animal's own juices as rep- 

 resented by the secretions from this organ. But the 

 vomero-nasal organ, particularly in mammals, is inti- 

 mately associated with much cavernous tissue whose 

 change in volume may be concerned with its filling and 

 emptying. Thus it is quite possible that oral or nasal 

 juices may be sucked into the vomero-nasal organ and 

 discharged from it as has recently been maintained by 

 Broman (1918). Henning (1916) has suggested that the 

 organ is concerned with water olfaction as contrasted 

 with air olfaction, but according to an unpublished obser- 



