308 Zoological Society. 



everted. When the animal is excited, and it is constantly highly ex- 

 citable, the eveision of the bag becomes complete, and its thick lips 

 being thrown widely back, the intervening space is actually forced 

 forwards so as to form a projection instead of a hollow: the animal 

 is, on such occasions, delighted to thrust repeatedly the naked lining 

 of the sac against any substance that is offered to him, which soon 

 becomes loaded with the odour that has been referred to as belonging 

 to the secretion. In the second individual, although it is perfectly 

 mature, the protrusion of the inner surface of the sac is not quite to 

 .so great an extent as in tlie more aged male ; and the less thickened 

 edges of the sinus allow of a nearer approximation to its closure in 

 the unexcited state of the animal. The youngest male has the lips 

 of the sinus small and closely applied to each otlier, so as to hide 

 completely the whole of the internal lining of the sac, and to exhibit, 

 externally, a mere fissure : in it the lips are but slightly moved when 

 the animal is interested. The emasculated individual, notwithstand- 

 ing its full growth, has its suborbital sinus nearly in the same condi- 

 tion as that of the immature male : it is merely a slight fissure, the 

 edges of which are closely applied to each other; and in it those 

 edges do not appear to be at all moved, the animal being generally 

 careless and inanimate. It would consequently seem that the same 

 cause which induced the retention, by this individual, of its immature 

 colours, and which arrested the perfect growth of its horns, was ade- 

 quate also for the checking of the development of the suborbital sinuses. 

 Those organs, therefore, would appear to be dependent on sexual per- 

 fection ; and consequently to be, in some manner yet to be ascertain- 

 ed, subservient to sexual purposes, with the capacity for which they 

 are evidently, in the phases of their development, essentially con- 

 nected. 



Mr. Owen, who had conceived it possible that the secretion of 

 these glands, when rubbed upon projecting bodies, might serve to di- 

 rect individuals of the same species to each other, remarked that he 

 had endeavoured to test the probability of this supposition by pre- 

 paring a tabular view of the relations between the habits and habitats 

 of the several species of Antelopes, and their suborbital, maxillary, 

 post-auditory, and inguinal glands ; in order to be able to compare 

 the presence and degrees of development of these glands with the 

 gregarious and other habits of the Antelope tribe. He stated, how- 

 ever, that it was evident from this table, that there is no relation be- 

 tween the gregarious habits of the Aritelopes which frequent the plains, 

 and the presence of the suborbital and maxiliary sinuses; since these, 

 besides being altogether wanting in some of the gregarious species, 

 are present in many of the solitary frequenters of rocky mountainous 

 districts. The supposition, therefore, that the secretion may serve, 

 when left on shrubs or stones, to direct a straggler to the general 

 herd, falls to the ground. 



Mr. Owen's Table is as follows : 



