212 PROFESSOR TURNER'S ACCOUNT OF THE GREAT FINNER WHALE 



in this locality. Lying outside the mammary gland was a muscle which, by its 

 contraction, would aid in expelling the milk along the ducts, and through the 

 orifice of the nipple. 



The size of the secondary ducts of this gland, and the dilatation of the single 

 central duct into a great reservoir for the collection of the milk, have obviously 

 special reference to the aquatic mode of life of an animal which suckles its 

 young. For, as John Hunter long ago pointed out,* the mode in which these 

 animals give suck is very inconvenient for respiration, as if the mother were to 

 turn round so as to elevate the nipple to the surface then her nares would be 

 under water ; whilst, if the mother remains in her normal position, then the 

 nose of the calf must be under water, and the time of sucking can only be 

 between each respiration. It is necessary, therefore, that the gland should be 

 so constructed as to allow of a considerable accumulation of milk in the ducts, 

 which may be readily drawn off by the calf in the intervals between the respi- 

 ratory acts. 



Baleen. — When the lower jaw was removed by cutting through the massive 

 fibrous columns, which connected the condyles of this bone to the base of the 

 skull, and when the occipito-atloid joint was disarticulated, the skull was turned 

 over on its dorsum, and a complete view of the roof of the mouth, and of the 

 baleen in situ was obtained. Extending from behind forward in the mesial 

 plane of the palate was the great central crest or keel, which was much broader 

 and more prominent posteriorly than anteriorly, and was covered on its 

 free surface by a black mucous membrane. Immediately on each side of the 

 base of the keel the palate was covered by a smooth and almost flat, black 

 mucous membrane, and external to this again was the lateral series, or wreath, 

 of deep black baleen plates with their inferior free edges fringed with black 

 setse. 



The wreaths of baleen plates on the two sides converged as they passed for- 

 wards, and at the anterior part of the mouth they became continuous with each 

 other, as is the rule indeed in the Finner whales.t Posteriorly, where they lay 

 close to the entrance into the gullet, they were separated by a considerable 

 interval ; though here also they inclined inwards to the base of the great mesial 

 palatal keel. The inner edge of each wreath had a curved outline with the 

 concavity towards the mesial keel. The outer edge was convex, and in its 

 curvature closely corresponded to that of the margin of the beak itself. This 

 border was bounded by a raised fold, the coronary or wreath-band (Horn- 

 Kranzband of Rosenthal), and was situated one foot within the outer edge of 

 the beak. Where the two wreaths became continuous in front, the junction 

 took place seven inches within the tip of the beak. 



* Structure and Economy of Whales. Phil. Trans. 1787. 



t Eschricht and Reinhardt. I. have also seen this in two specimens of Balcunoptera rostrata. 



