CAREFUL AND FREQUENT OBSERVATIONS 35 



Fia. 50. A simple form of breeding cage. 



FIG. 57. A home-made breeding 

 jar for aquatic insects. 



FIG. 58. Corn growing between two 



FIG. 59. A, vertical section of moist 



glass plates for study of root forms. (After chamber used in relaxing dried specimens. 



Comstock.) 



B, partition of brass or copper gauze, sup- 

 ported at o, upon which insects are laid. 



