NO. 1 8 



SENSE ORGANS OF COLEOPTERA — McINDOO 



snugly, and then a dark green window shade (fig. 2, A) was pulled 

 to the bottom of the window. The door (B) was made light-proof by 

 fastening strips of black cloth around all its edges, and its transom 



^- 



D 



y^^ 



K 



N 



Q 



Fig. 2. — Diagram of a constant temperature and iuiniidity dark-room, sliowing 

 parts of room and ajjparatus used in testing photo-geotaclic responses of Mexican 

 bean beetle. Tbe parts and apparatus are as follows: A, window shade; B, door; 

 C, ventilator; I), box; E, table; /'". lawn sprayer; G, garden hose; H, bath 

 towels; /, hygrothermograph ; J, thermometer; K, outlet water pipe; L, electric 

 fan; M, photo-geotactic box; A^, water screen; O, electric lamp; P, siphon run- 

 ning to water screen ; Q, siphon running from water screen ; and R, stool. 



was changed into a ventilator (C) through which air passed freely, 

 but no light. The temperature and humidity were partially controlled 

 by the following means. A box (D), 40 inches long, 24 inches wide, 



