472 Dynamic Theory. 



rodents, especially mice, have an appreciation of music without being, 

 able to make it themselves. But there are some possessed of very 

 respectable musical powers. Mr. Lockwood, in the American Natural- 

 ist for Dec., 1871, gives an account of a musical vesper mouse, or wood 

 mouse (Hesperomys Cognatus^ which came into his possession. This little 

 animal did most of her singing at night, and she had several songs in 

 the major key of B. u Her soft clear voice falls an octave with all the 

 precision possible. " On one occasion she sang continuously for nine 

 minutes, during which time she performed all her regular tunes, adding 

 new and beautiful variations. One measure was so silvery and soft that 

 Mr. L. said to a lady who was listening'that, ' ' a canary able to execute 

 that would be worth a hundred dollars." Her pauses between the roles 

 did not, on this occasion, exceed a second. She often kept up her sing- 

 ing while eating, and while in her revolving wheel. She had a particu- 

 lar song for the wheel. Mr. L. also mentions a common mouse owned 

 by a friend of his. which was a rather indifferent singer. He states 

 that there have been singing rats, and that several varieties of squirrels 

 are capable of musical sounds. Mr. W. 0. Hiskey, of Minneapolis, 

 also reported to the American Naturalist for May, 1871, an account of 

 a musical prairie mouse, Hesperomys Micliiganensis ( as supposed ). He 

 found him in a closet in an overshoe filled with pop- corn which he had 

 stolen from a basket near by. He was singing something like a canary 

 bird. Mr. H. observed him for ten minutes not more than four feet 

 away. < ' His song was not a chirp, but a continuous song of musical 

 tone, a kind of to-wit-to-wee-woo-woo-wee-woo, quite varied in pitch. " 

 He did not succeed in capturing the little musician. 



CHAPTER XLIX. 



SMELL. 



The cavities of the nose, mouth, &c , which have been formed by in- 

 vagination or a doubling in from the outside, are lined with a continua- 

 tion of the outside skin, which in its interior position acquires some 

 slight modifications and receives the name epithelium. The front end 

 of the brain rests upon a portion of the skull called the ethmoid or sieve 

 bone ( or sometimes the cribriform bone, which means the same). This 

 bone in front is composed of many fragile laminae or plates separated 

 and forming numerous cavities. It articulates above with the frontal 

 bone which bounds the front end of the brain and forms the forehead. 

 The front walls of this bone consist of two layers considerably sepa- 

 rated from each other, forming two large cavities, one on each side of the 

 root of the nose, and called frontal sinuses. These open below and con- 



