4 



Professor Flower 



[May 25, 



Escbricht and Eeinhardt counted in a new-born Greenland Eight 

 Whale (Balcena mysticetus) sixty-six hairs near the extremity of the 

 upper jaw. and about fifty on each side of the lower lip, as well as a 

 few around the blowholes, where they have also been seen in Megap- 

 tera longimana and Balcenoptera rostrata. In a large Rorqual 

 (Balcenoptera musculus), quite adult and sixty-seven feet in length, 

 stranded in Pevensey Bay in 1865, there were twenty-five white, 

 straight, stiff hairs about half an inch in length, scattered somewhat 

 irregularly on each side of the vertical ridge in which the chin ter- 

 minated, extending over a space of nine inches in height and two and 

 a half inches in breadth. The existence of these rudimentary hairs 

 must have some significance beyond any possible utility they may be 

 to the animal. Perhaps some better explanation may ultimately be 

 found for them, but it must be admitted that they are extremely 

 suggestive that we have here a case of heredity or conformation to a 

 type of ancestor with a full hairy clothing, just on the point of 

 yielding to complete adaptation to the conditions in which whales now 

 dwell. 



In the organs of the senses the Cetacea exhibit some remarkable 

 adaptive modifications of structures essentially formed on the Mam- 

 malian type, and not on that characteristic of the truly aquatic 

 Vertebrates, the fishes, which, if function were the only factor in the 

 production of structure, they might be supposed to resemble. 



The modifications of the organs of sight do not so much affect the 

 eyeball as the accessory apparatus. To an animal whose surface is 

 always bathed with fluid, the complex arrangement which mammals 

 generally possess for keeping the surface of the transparent cornea 

 moist and protected, the movable lids, the nictitating membrane, the 

 lachrymal gland, and the arrangements for collecting and removing the 

 superfluous tears when they have served their function cannot be 

 needed, and hence we find these parts in a most rudimentary condition 

 or altogether absent. In the same way the organ of hearing in its 

 essential structure is entirely mammalian, having not only the sacculi 

 and semicircular canals common to all but the lowest vertebrates, but 

 the cochlea, and tympanic cavity with its ossicles and membrane, all, 

 however, buried deep in the solid substance of the head ; while the 

 parts specially belonging to terrestrial mammals, those which collect 

 the vibrations of the sound travelling through air, the pinna and the 

 tube which conveys it to the sentient structures within are entirely or 

 practically wanting. Of the pinna or external ear there is no trace. 

 The meatus auditorius is certainly there, reduced to a minute aperture 

 in the skin like a hole made by the prick of a pin, and leading to a 

 tube so fine and long that it cannot be a passage for either air or 

 water, and therefore can have no appreciable function in connection 

 with the organ of hearing, and must be classed with the other 

 numerous rudimentary structures that whales exhibit. 



The organ of smell, when it exists, offers still more remarkable 

 OTidence of the origin of the Cetacea. In fishes this organ is specially 



