CHAPTER II 

 FEEDING, BREEDING, AND DEVELOPMENT or THE YOUNG 



IN this chapter I shall report, for the benefit of those who 

 may wish to know how to take care of dancing mice, my 

 experience in keeping and breeding the animals, and my 

 observations concerning the development of the young. It 

 is commonly stated that the dancer is extremely delicate, 

 subject to diseases to an unusual degree and difficult to 

 breed. I have not found this to be true. At first I failed to 

 get them to breed, but this was due, as I discovered later, to 

 the lack of proper food. For three years my mice have bred 

 frequently and reared almost all of their young. During one 

 year, after I had learned how to care for the animals, when 

 the maximum number under observation at any time was 

 fifty and the total number for the year about one hundred, I 

 lost two by disease and one by an accident. I very much 

 doubt whether I could have done better with any species of 

 mouse. There can be no doubt, however, that the dancer 

 is delicate and demands more careful attention than do 

 most mice. In March, 1907, I lost almost all of my dancers 

 from what appeared to be an intestinal trouble, but with this 

 exception I have had remarkably good luck in breeding and 

 rearing them. 



My dancers usually were kept in the type of cage of which 

 Figure 2 is a photograph. 1 Four of these double cages, 



1 This cage was devised by Professors W. E. Castle and E. L. Mark, and 

 has been used in the Zoological Laboratories of Harvard University for several 

 years. 



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