528 
BIONOMIC NOTES 
The evidence as to the other species experimented with fails to 
convince me one way or the other. 
During the summers of 1909 and 1910 Mr. R. I. Pocock, F.R.S., 
conducted an important series of experiments in the gardens of the 
Zoological Society of London. Butterflies of many species, a few 
Moths, Lepidopterous larvae; conspicuous Beetles, such as Carabus , 
Timarcha, Bhagonycha , and Coccinella ; Bees and Dipterous flies that 
appear to mimic them, as well as several creatures belonging to other 
groups, were offered to various Mammals and Reptiles, as well as 
quite a large number of Birds. 
Mr. Pocock, after explaining the difficulties attending his experi¬ 
ments, says: “ Two facts struck me very forcibly. . . . The first was 
the exceeding keenness of the birds for the insects brought to them. 
. . . The living prey was evidently a great treat to them; and over 
and over again I was impressed with the persistence shown by birds 
in persevering with insects that were obviously not to their liking, 
returning to the morsels repeatedly as if food of such a nature was 
too good to be wasted ... it is quite clear that the plain record of an 
insect being eaten is no proof of its palatability. Better evidence . . . 
is supplied by the behaviour of the bird towards it. . . . The second 
fact . . . the insectivorous birds in our aviaries seemed to know at once 
what the butterflies were; they were on the alert the moment one was 
liberated and pursued it with determination and precision, following 
its every turn and twist, and either catching it upon the wing or 
pouncing upon it after settling. . . . Again, unless the species of butter¬ 
flies used for the experiments are, or were in the past, habitually preyed 
upon by birds, whence comes the extraordinary skill the liberated 
specimens . . . displayed in dodging the swoop of the birds in 
mid-air ? ... With regard to the experiments on mimicry, especially 
those made with Volucella bombylans and Bombus hortorum, it appears 
to me that they satisfy all that the theory, as propounded by Bates, 
demands. . . . They show that several species of birds, after learning 
by experimental tasting that Bombus hortorum is unpalatable, refused 
to touch Volucella bombylans .” 1 
The paper deserves careful perusal, and the writer is proud to 
have been able to supply some of the material for the experiments. 
1 “ On the Palatability of Some British Insects, etc.,” R. I. Pocock, F.R.S., etc. 
With notes by Prof. E. B. Povilton, F,R*S, Proc. Zool. Soc. Lond ., 1911, pp. 
809-868, 
