56 SPIRACULA OF ANIMALS. 



that I know of, been noticed by any naturalist. For it Ijoka 

 as if tliese creatures would not be suffocated, though both 

 their mouths and nostrils were stopped. This curious forma- 

 tion of the head may be of singular service to beasts of 

 chase, by affording them free respiration ; and no doubt 

 these additional nostrils are thrown open when they are 

 hard run.* Mr. E-ay observed that at Malta, the owners 



* In answer to this account, Mr. Pennant sent me the following curious 

 and pertinent reply : — " I was much surprised to find in the antelope something 

 analogous to what you mention as so remarkable in deer. This animal also 

 has a long slit beneath each eye, which can be opened and shut at pleasure. 

 On holding an orange to one, the creature made as much use of those orifices as 

 of his nostrils, applying them to thefruit, and seeming to smell it through them." 



[The structure of the glandular cavities, of which the orifices are here alludad 

 to, precludes the possibility of their ever being used as accessory respiratory 

 passages, or organs of scent. 



The common integument is continued over the margins of the orifice, and 

 is reflected over the whole of the interior of the cavity, which is altogether 

 imperforate, except by the ducts of a large flattened mucous gland, which 

 occupies its base ; a few short hairs spring up in the interspaces of the terminal 

 orifices of the ducts. Mr. Hunter, whose attention was probably called by his 

 friend Pennant to this peculiarity of the deer and antelopes, has left several 

 preparations of the glands and sinus, taken from the Indian and another species 

 of antelope, and also from the deer ; in which their condition as tegumentary 

 sacs, having no communication with the nose, is clearly shown. 



Conceiving that the secretion of these glands, when rubbed upon projecting 

 bodies, might serve to direct individuals of the same species to each other, I 

 prepared 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 develop- 

 ment of the glands, with the gregarious and other habits of the antelope tribe. 



From this table it was, however, evident, that there is no relation between 

 the gregarious habits of the antelopes which frequent the plains and the presence 

 of the suborbital and maxillary 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 might serve, when left on shrubs or stones, to guide a straggler to 

 the general herd, falls to the ground. 



The secretion of those cutaneous glands which are designed to attract the 

 sexes, is generally observed to acquire towards the reproductive period a strong 

 musky odour, as in the elephant and alligator; but the secretion of the subor- 

 bital sinuses, even when these are most fully developed, is devoid of any 

 approach to a musky, or any other well defined odour. 



Nevertheless, the subjoined observations of Mr. Bennett tend to give some 

 probability to the theory which ascribes to the suborbital sinuses a sexual 

 relation. — R. O.] 



[It seems probable that these organs, on the use of which it is by no means 



