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APPENDIX. 



always he taken that their quarters do not become in the 

 least foul. 



A very convenient form of breeding-cage or vivarium 

 is shown in Fig. 2, and is thus described by Mr. Riley: 



Fig. 2.— Breeding-cage, described in the text. 



"It comprises three distinct parts: first the bottom board 

 {a), consisting of a square piece of inch-thick walnut 

 with a rectangular zinc pan (//') four inches deep fastened 

 to it above, to prevent cracking or warping, facilitate lift- 

 ing, and allow the air to pass underneath the cage. 

 Second, a box (/;), with three glass sides and a glass door 

 in front, to fit over the zinc pan. Third, a cap (c) which 

 fits closely to the box, and has a top of fine wire gauze. 



