1912.] NATURAL SCIENCES OF PHILADELPHIA. 295 



air about him, as of one suffering from an overdose of Doryphora.. 

 Though kept some two weeks with no other food, neither Bufo would 

 touch a spearman again." 



No better illustration could be asked of the misleading character 

 of experimental results nor, it may be added, of the highly imagina- 

 tive conclusions drawn therefrom. Notwithstanding the "dolorous 

 air" of these toads by reason of potato-beetle diet, the fact remains 

 that toads habitually feed on potato beetles. Tenney, 23 Riley, 24 

 Kirkland, 25 Garman, 26 and Chittenden 27 among others record toads 

 as enemies of potato beetles. The writer has found the remains of 

 no fewer than twelve Leptinrfarsa decemlineata in a single casting 

 of a toad. 



Frogs. — In an article entitled, ''Habit Formation in Frogs," 28 

 A. A. Schaeffer says: "Individuals of three different species of 

 frogs, Rana clamata, R. sylvatica, and R. virescens learned to avoid 

 disagreeable objects, such as hairy caterpillars, in from four to seven 

 trials or possibly less. Such habits persisted for at least ten days, 

 but this point was not thoroughly tested. 



A Rana clamata formed a habit of avoiding earthworms treated 

 with chemicals in two trials. This habit persisted perfectly for only 

 a short time, covering five trials in about twenty-two hours. The 

 habit persisted somewhat imperfectly for five days. After an electric 

 stimulus had been applied, earthworms were not eaten for seven days, 

 although mealworms were eaten" (p. 334). 



These observations point to the conclusion that any color may 

 be regarded as warning, provided a sufficiently disagreeable impres- 

 sion becomes associated with it. 



Another experimenter, Charles W. Hargitt, was led to doubt the 

 quick formation of such associations by Hyla, as is shown by his 

 comments on the behavior of a tree frog toward Hymenoptera. In 

 food taking, he says: "Hyla behaves quite similarly to others of 

 its kind. It seems not to notice any except moving objects. A 

 spider may remain quietly in a given part of the cage for hours or 

 days undisturbed. If it assume an active attitude it is almost 

 certain to be taken very promptly. It is thus with any prey. The 

 insects most commonly supplied were flies, small beetles, grass- 



23 Amer. Nat., 5, 1871, pp. 170, 171. 



24 Fourth Mo. Rep., 1872, p. 16, and in many other publications. 



25 Bui. 46, Hatch Agr. Exp. Sta., 1897, p. 25. 



26 Bui. 91, Ky. Agr. Exp. Sta., 1901, p. 66. 



27 Circ. 87, U. S. Bur, Ent., 1907, p. 12. 



2S Journ. An. Behavior., Vol. 1, No. 5, Sept.-Oct., 1911, pp. 309-335. 



