642 THE SPOUTING AND MOVEMENTS OF WHALES. 



actively, which excludes the possibility of sleep, even if we admit 

 that the necessaiy movements of respiration could be automically per- 

 formed, as Jouan supposes (1882), for it is not possible to maintain 

 that the whales could follow automaticall}^ a ship the course of w'hich 

 is variable. 



It is possible to form three hypotheses regarding the sleep of 

 whales. One can suppose, first, that the}^ sleep at the bottom of the 

 sea. Buchet (189.5) is of this opinion, and believes what the fishermen 

 told him on this subject, for he says: "They [the whales] often emerged 

 suddenly- all around the ship without having been seen at a distance." 

 This applies to the heavy whales and the porpoises which would sleep 

 at night. The fact which Buchet reports as a proof of the correctness 

 of his opinion is explained in quite another manner. It is not a mat- 

 ter for astonishment to see animals suddenly appear, which swim as 

 much as 12' miles an hour (Scoresby, 1820) and can remain under water 

 more than half an hour. 



The opinion of Buchet can not be accepted for many reasons. Ceta- 

 ceans could sleep but poorly at the bottom of the sea, since they are 

 obliged to ascend to breathe. When they inhabit deep seas they could 

 not sleep, for the cetaceans do not dive to a great depth. Their skin 

 is so delicate that the contact with the bottom would be injurious to 

 them. I do not believe, therefore, that this first hypothesis can be 

 maintained. 



1 will note here merely for reference a curious work of Barkow 

 (1802) which is connected with the h3'pothesis which I am about to 

 examine and which contains the following conclusions: "The summer 

 life of the whalebone whales is preeminently^ the life of the mammals 

 depending on atmospheric lungs; their winter life preeminently a sub- 

 marine life, depending on the abdominal vessels (Darmgefassleben)." 

 This author therefore considers the cetaceans as hibernating animals, 

 which pass a part of their existence at the bottom of the sea. He 

 reaches this strange deduction as a result of erroneous conclusions, 

 regarding which I will not enter into details here. 



The second hj^pothesis that can be put forward is also improbable, 

 namel}", that the cetaceans sleep at the surface. It is well known, 

 indeed, that the cetaceans, which are heavier than the water, could not 

 maintain themselves at the surface except by swimming. The genus 

 Balsena makes the single exception — the right whales float, but the}^ 

 float on the back (which is ver}^ much heavier than the belly) if the}" do 

 not maintain themselves actively in the natural position. This brings 

 matters to the same point as in the case of the heavy cetaceans — in the 

 one instance as in the other the blowhole would be below the surface. 



The third hypothesis is much more plausibk. In sleeping whales 

 execute automatically the movements necessary to respiration. It is 

 well known that horses in harness can sleep perfectly well while pull- 



