MYSTACOCETI. 65 



handicapped. The prevalent idea that Whales spout " water " 

 from the blowhole is erroneous, the so-called "spouting" or "blow- 

 ing " being caused merely by the forcible expulsion of the air taken 

 at the last inspiration, and which, charged by the action of the 

 lungs with humid vapor, changes, upon contact with the colder air, 

 into a jet of combined steam and spray. All the Cetaceans are 

 predacious, living entirely on animal food of one form or another, 

 this consisting of fishes, small swimming and floating crustaceans, 

 pteropods, jelly fish ( 'Medusfp,), and cephalopods, the latter form- 

 ing almost the sole food of the Sperm Whales, without doubt the 

 largest of living animals, and from the non-assimilization of cer- 

 tain portions of these Cephalopods the valuable substance known 

 as " ambergris " is derived ; one genus fOrcaJ, however, habitu- 

 ally feeds also on the larger mammals, such as Seals, Porpoises, 

 Dolphins, and even attacks the larger Whales. With few excep- 

 tions they are timid and inoffensive, active in their movements, 

 and markedly affectionate towards one another, especially in the 

 case of the mother to her young, which, if harpooned, she will 

 never desert, even when she herself receives the fatal stroke. The 

 young number generally one, never more than two, at a birth, 

 and the mother at the time of gestation seeks the protection of 

 shallow sheltered bays and inlets, and is therefore all the more 

 liable to these murderous attacks at the very time that the law 

 should most stringently and sternly protect her. Most of the 

 species of Cetaceans are gregarious, in the case of some of the 

 Delphinidce as many as thousands hunting in a single pack. 



The earliest fossil Cetacea, of whose organization anything like 

 a complete knowledge is evident, are the Zeuglodons of the Eocene 

 period. 



Suborder I. Mystacoceti. 



Whale-bone "Whales. 



Teeth never functionally developed, disappearing before the 

 birth of the foetus. Palate provided with plates of baleen, 

 (whalebone). Skull symmetrical. Nasal bones forming a roof to 

 the anterior nasal passages, which are directed upwards and for- 

 wards. External openings of nostrils distinct from each other, 

 longitudinal. Olfactory organ distinctly developed. Maxilla 

 produced in front of, but not over, orbital process of frontal. 

 Lachrymal bones small, distinct from the jugal. Tympanic bone 

 anchylosed to the periotic, which is attached to the base of the 

 cranium by two strong diverging processes. Kami of mandible 

 arched outwards, their anterior ends meeting at an angle, and 

 without true symphysis. Ribs articulating only with the trans- 

 verse processes of the vertebrse. Sternum composed of a single 

 piece, and articulating with a single pair of ribs only. No ossified 

 sternal ribs. A short conical crecum. 



E 



