4 Introduction 



mere suggestions as to how to get living specimens, to measured pro- 

 cedures quantitatively determined. We have filled some of the more 

 obvious gaps with abstracts and reprintings (initialed by the editor 

 responsible) from available literature but we have by no means ex- 

 hausted this source of material. 



The contributed articles are arranged as far as possible in systematic 

 order following Pratt's Manual oj the Common Invertebrate Animals 

 (revision of 1935), with the orders of insects following that of Com- 

 stock's Manual jor the Study oj Insects (1926 edition) . Material within 

 the insect orders is arranged according to the N. Y. State List oj Insects. 



Since from the nature of the book the different types of procedure 

 are widely scattered through its pages, we have tried to make an index 

 that would serve as a finding list for them, and we recommend that the 

 user consult the index freely. 



We have assumed on the part of the reader some acquaintance with 

 general zoology and some knowledge of elementary laboratory tech- 

 nique. Limitations of space have necessitated that we restrict the text 

 rather closely to collecting and culture methods. In doing so we have 

 had to omit some interesting and valuable material, principally intro- 

 ductory remarks, systematic discussion, life history details, and sugges- 

 tions for the use of the materials in special fields. We have also done 

 some condensing to avoid undesirable duplications, and we hope that in 

 so doing we have not been unfair to any of our helpfully minded col- 

 laborators. Papers by members of the scientific staffs of federal depart- 

 ments and bureaus have come to us each bearing a statement that it is 

 offered for publication with the permission of the head of the Depart- 

 ment concerned. Receipt of these statements is hereby acknowledged; 

 but the statements themselves are omitted from the text to make room 

 for more useful material. 



It is hoped that this compilation on culture methods may stimulate 

 interest in maintaining living animals in biological laboratories and may 

 lead to further development of the proper technique. We will be glad 

 to hear comments from the users of this book upon the usefulness of the 

 methods here offered and to learn of new developments in the use of 

 them; for it seems highly probable that both eliminations and improve- 

 ments resulting from further trials will make necessary an early revision 

 of this compendium. 



