STRANDED AT LONGNIDDEY. 225 



walls, by crypt-like depressions in the mucous membrane, some of which were 

 large enough to admit a kidney bean, others not bigger than a pea (figs. 30, 31). 

 These crypts were collected into groups, the best marked of which were situated 

 close to the junction of the anterior border of the soft palate with the anterior 

 wall of the pharynx. 



In studying the method by which this and other whalebone whales collect 

 their food in their huge mouths prior to deglutition, it should be kept in mind 

 that they are not provided either with teeth, or with a protrusible tongue by 

 which to grasp the prey. It is probable that when in search of food, the animal 

 swims about with its mouth wide open, until a sufficient quantity of food is 

 collected on the dorsum of the tongue, in the space between the two halves of 

 the mandible, prior to being swallowed. 



Though the depression of the lower jaw in the act of opening the mouth 

 is doubtless due to muscular action, yet, when once open, the jaw may, I 

 believe, remain depressed without the continued action of muscles. The huge 

 fibrous columns, which pass, one on each side, from the base of the skull to the 

 condyles of the lower jaw, so suspend that bone, as to support it without the 

 need of calling into action any muscle ; for it was observed, as the animal was 

 floating at high water, that the lower jaw was open, and swayed gently to and 

 fro with the movements of the waves. To draw the jaw back prior to degluti- 

 tion, the temporal and other elevator muscles must be called into action ; and, as 

 the jaw is raised, the tongue is pressed upwards against the lower edges of the 

 baleen, and the water contained in the cavity of the mouth is forcibly squeezed 

 out between the rows of plates. The food retained in the mouth by the sieve- 

 like fringes of the baleen, is then forced back through the bucco-pharyngeal 

 canal, doubtless by the action of the tongue, into the pharynx, when the con- 

 strictors grasp it and force it back into the oesophagus. Here the soft palate 

 acts as a valve to prevent its passage upwards to the nose, and the superior 

 laryngeal orifice is closed by the co-aptation of the epiglottis, arytenoid cartilages, 

 and aryteno-epiglottidean folds of mucous membrane, so that it cannot enter the 

 larynx. In these respects, therefore, the mechanical arrangements for prevent- 

 ing the passage of the food into the respiratory passages, closely remind one 

 of the structures found in the corresponding locality in the human subject. 

 As it is also important that water should not pass from the mouth into the 

 pharynx whilst the animal is collecting its food ; and as the respiratory process 

 is performed, not by the mouth but by the nose, the contraction of the fibres of 

 the palato-glossal sphincter would effectually close up the bucco-pharyngeal 

 canal at the time when these processes were going on. 



The stomach was so injured in various places by the men engaged in flensing 

 the animal, that little more was ascertained in connection with it, than that it 

 was subdivided into at least four compartments, which communicated with each 



VOL. XXVI. PART I. 3 N 



