PREFACE 



This book has been prepared as an aid to studies that 

 require living animals in continuous supply. They 

 are needed both jor teaching and for research, espe- 

 cially for research in genetics, in parasitology, in experi- 

 mental zoology, in economic entomology, and in nearly every 

 field of applied biology. They are needed in aviaries, in 

 aquaria, in fish culture experiment stations, and in zoological 

 gardens where they are used as food for carnivorous animals. 

 Such needs have seemed to justify an effort to gather to- 

 gether the experience of many scattered workers and make 

 their useful results more widely available. 



The task of the committee in charge has been a simple 

 one — that of serving as a medium for the exchange of ex- 

 perience by actual workers. So we have announced the under- 

 taking to the zoological public and we have personally 

 invited contributions from those we have known to be keeping 

 cultures of small animals. We have put together with a 

 minimum of editing what they have offered. Our responsi- 

 bility ends here. The articles bear the names of their con- 

 tributors. We do not guarantee the methods outlined. Indeed, 

 there are great difficulties in keeping cultures going, and 

 failures will occur betimes even in the hands of careful 

 workers. Constant alertness is required to see that fit con- 

 ditions are maintained, and a large measure of ingenuity is 

 often necessary to adapt places and circumstances to keeping 

 conditions fit. 



