340 PHILOSOPHICAL TRANSACTIONS. [aNNO 1787. 



it is the air retained in the nostril out of the current of respiration, which by 

 being impregnated with the odoriferous particles contained in the v/ater during 

 the act of blowing, is applied to the organ of smell. It might be supposed that 

 they could smell the air on the surface of the water by every inspiration, as ani 

 mals do on land; and probably they may: but this will not give them the power 

 to smell the odoriferous particles of their prey in the water at any depth ; and as 

 their organ is not fitted to be affected by the application of water, and as they 

 cannot suck water into the nostril, without the danger of its passing into the 

 lungs, it cannot be by its application to this organ that they are enabled to 

 smell. 



Some have the power of throwing the water from the mouth through the 

 nostril, and with such force as to raise it 30 feet high: this must answer some 

 important purpose, though not immediately evident to us. As the organ appears 

 to be formed to smell air only, and as I conceive the smelling of the external air 

 could not be of use as a sense, I therefore believe that they do not smell in in- 

 spiration ; yet let us consider how they may be supposed to smell the odoriferous 

 particles of the water. The organ of smell is out of the direct road of the 

 current of air in inspiration ; it is also out of the current of water when they 

 spout; may we not suppose then, that this sinus contains air, and as the water 

 passes in the act of throwing it out, that it impregnates this reservoir of air, 

 which immediately affects the sense of smell ? This operation is probably per- 

 formed in the time of expiration, because it' is said that this water is sometimes 

 very offensive; but all this I only give as conjecture. If the above solution is 

 just, then only those which have the organ of smell can spout, a fact worthy of 

 inquiry. The organ of smell would appear to be less necessary in these animals 

 than in those which live in air, since some are wholly deprived of it; and the 

 organ in those which have it is extremely small, when compared with that of 

 other animals ; as well as the nerve which is to receive the impression, as was 

 observed above. 



Of the sense of hearing. — The ear is constructed much on the same prin- 

 ciples as in the quadruped; but as it differs in several respects, which it is 

 necessary to particularize, to convey a perfect idea of it the whole should be 

 described. As this would exceed the limits of this paper, I shall content my- 

 self with a general description, taking notice of those material points in which 

 it differs from that of the quadruped. This organ consists of the same parts as 

 in the quadruped; an external opening, with a membrana tympani, an eusta- 

 chian tube, a tympanum with its processes, and the small bones. There is no 

 external projection forming a funnel, but merely an external opening. We can 



similar to the breathing of fish, it not being the water which produces the effect there, but the air 

 oatained in it. This I proved by experiments, and is mentioned by Dr. Priestley. — Grig. 



