HEREDITY OF WILDNESS AND SAVAGENESS IN MICE 63 



where wildness seems to behave in a similar manner, as for 

 instance, in chart 2 (F2a, 9 420 with c? 377) and in chart 3 

 (Fab, 9 894 with d^ 893). 



While the segregation of the various determining factors of 

 savageness or wildness and their behavior as a recessive or, 

 as it seems in some instances, a dominant, apparently explains 

 the inheritance in these various crosses, the number of matings 

 giving such results is comparatively few, hence, a statement 

 more definite than a mere suggestion of a possibility must 

 necessarily be left until a further study in this particular field 

 has been made. 



OBSERVATIONS ON "SINGING" IN MICE^ 



In the literature of animal behavior appear several refer- 

 ences, to the production by mice of sounds of musical quality. 



The "singing" of mice is described variously by different 

 writers. Lee (1878) states that it consists of a series of chirps 

 at the rate of three or four per second. At the beginning of 

 the series, the chirps are low but gradually they become louder. 

 The "song" of one mouse this author likens to the sweet and 

 varied warbling of a canary. Every note was "clear and dis- 

 tinct." 



In referring to the same phenomenon, the naturalist Brehm 

 (1896), attributes the following descriptions to various observ- 

 ers. One informant states that the "song" is an irregular 

 mixture of chirps and trills with here and there a snarling, 

 smacking sound followed by a low murmur. Another describes 

 it as a twitter which is a mixture of long drawn squeaking and 

 piping sounds which may be heard at a distance of twenty 

 paces. 



One observer noted the phenomenon only in the case of a 

 female mouse while giving birth to young, while another ob- 

 server states that only the male "sings." 



The majority of those who have heard "singing" in mice 

 have assumed that it is due to a diseased condition of the lungs 

 or of the vocal organs, but conditions so diverse as pregnancy 

 and parasites in the liver have also been suggested as causes. 



- Revised note which appeared under heading of Singing Mice, Journal of 

 Animal Behavior, 1912, ii, No. 5, pp. 363-366. 



