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,” Riley,” 
Kirkland,?* Garman,?° and Chittenden?’ among others record toads 
as enemies of potato beetles. The writer has found the remains of 
no fewer than twelve Leptin-tarsa decemlineata in a single casting 
of a toad. 
Frocs.—In an article entitled, “Habit Formation in Frogs,’”> 
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 Bul. 46, Hatch Agr. Exp. Sta., 1897, p. 25. 
26 Bul, 91, Ky. Agr. Exp. Sta., 1901, p. 66. 
27 Circ. 87, U. S. Bur. Ent., 1907, p. 12. 
28 Journ. An. Behavior., Vol. 1, No. 5, Sept.—Oct., 1911, pp. 309-335. 
