128 THE ZOOLOGIST. 



or, in other words, requiring about the same quantity of food for 

 their support, it follows that, both being supplied with an 

 apparatus of a similar nature for its capture, the draining power 

 of the apparatus in both cases must be the same. Both are 

 inoffensive, the Eight Whale depending on its diving powers for 

 its survival, is short and robust, adapted to withstand a great 

 pressure, and to remain a considerable length of time under 

 water. Along with these powers, great speed is unnecessary, 

 perhaps impossible. Accordingly we find this animal provided 

 with a draining apparatus (if I may use a convenient expression) 

 of enormous size, its baleen-plates of great length, slow in its 

 movements, and sluggish in its habits. B. sihhaldii, on the con- 

 trary, presents reverse characters, depending on its speed for its 

 survival ; we find it an animal of exceeding length, flattened 

 laterally, and greatly prolonged hindward — characters all calcu- 

 lated to suggest speed. Witness also the great vertical strength 

 of the rump, the draining apparatus necessarily small, and its 

 baleen-plates short, swift in its movements, and active in its 

 habits. Thus it becomes evident that, great as is the difference 

 in length of the baleen-plates of B. mysticetus and B. sihhaldii, 

 and consequently also in the size of their draining apparatus, 

 this difference may be equalised by slowness of motion on the 

 one hand, by swiftness on the other — in short, that the power 

 of the draining apparatus of the one is about equal to that of 

 the other. 



If, then, the above reasoning is correct, these two huge 

 creatures, depending on the same source of food for their 

 existence, differ from one another essentially only in one im- 



distends after death, a phenomenon to be accounted for apparently, m the 

 first place, by the relaxion of the respiratory ninseles on the cessation of 

 rigor mortis, and the conseqiient increase in the size of the chest thereafter, 

 but mainly by the generation of gases. In the course of a few daj-s a 

 Greenland Whale will resemble a balloon rather than a cetacean. One killed 

 by Capt. Gray in the ' Active,' in the year 1866, was found to measure, only 

 six days after being killed, 43 feet across the chest from tip to tip of the fins; 

 the girth was most probably greater than the entire length of the animal 

 (about 55 feet). Thus it is probable that the gi'eat girth (46 ft.) of the Finuer 

 stranded at Longniddry was likewise largely owing to this latter cause, and 

 that the girth, and consequently also the bulk, of Sibbald's Eorqual may 

 have been somewhat over-estimated. 



