630 
Mr. G. L. Bates on the 
belonging to the genus Phyllostrophus —more so even, in 
some of them, than in the specimen of Pycnonotus gabonensis 
figured (text-fig. 21, p. 629). In all species of Andropadus 
and particularly in A. virens, the lateral branches were 
found to be weak, consisting of a few small semiplumes 
only. The following is a list of the species in which the end 
of the spinal tract was found to be branched; generally more 
than one specimen of a species was examined :— Criniger 
chloronotus , C. calurus, Bleda synductyla, B. tricolor, Phyllo- 
strophus simplex, P. flavigula , P. falkensteini, P. leuco- 
pleurus, Andropadus indicator, A. clamans, A. gracilirostrisj 
A. gracilis, A. virens, A. latirostris, Pycnonotus gabonensis, 
Ixonotus guttatus . 
No adult bird of the Family Pycnonotidse was found to be 
entirely without these transverse branches at the end of the 
spinal tract; and no bird of any other family was found to 
have them. It should be added that they were not usually 
apparent in nestlings. 
II. Do the Birds of Southern Cameroon eat Butterflies ? 
The question in regard to birds feeding on butterflies is 
of interest to ornithologists as well as to entomologists. 
I believe that the birds of the West African forest do not 
feed to any great extent on butterflies. This belief is not 
based merely on the fact that I have not seen them do so, 
for such merely negative evidence is of little value. It is 
based on the fact that the stomachs of a large number of 
birds examined were without any remains of butterflies 
that were identified as such. During half a dozen years in 
which I kept records of a considerable proportion of all 
birds skinned, not only as to whether fruits, or seeds, or 
insects were found in the stomachs, but also the kinds of 
insects found when these could be easily made out, I never 
recorded a single instance of finding a butterfly or part of 
one; and during several months, w 7 hen my attention was 
particularly directed to that matter, I recorded in the cases 
of 178 insect-eating birds, the stomachs of which were 
examined, that nothing looking like remains of butterflies 
