130 
SPOLIA ZEYLANICA. 
as described (Fig. 7). In the example figured a small tag of the 
fibre by which it was suspended to the leaf is seen at the mouth of 
the tube. The butterflies emerged fourteen or fifteen days after 
commencement of pupation and proved to be S. gremius. 
A. WILLEY. 
Colombo, 1909. 
2. The Colombo Crow (Corvus splendens)—a case of the Survival of 
the Fittest. —I have had occasion during six or seven years to study 
the habits of this bird in the immediate neighbourhood of my house, 
the Artillery Mess, and Military Hospital on the Galle Face. The birds 
here are somewhat isolated from their fellows, and five in a small 
community of their own, and I have no doubt, judging by one which 
has a tin ticket round its neck, five their lives in this small area and 
seldom or never venture out of it. The consequence is there is a 
struggle for existence, the food-supply which is limited being 
constant, but the bird population having a natural tendency to 
increase. It would seem that the birds themselves recognize this, 
and make some attempts to regulate matters in the following way. 
The normal number of eggs in a clutch is four, but I have never seen 
as many as three young crows off the nest, and very rarely two ; the 
almost invariable number is one. So far I never found four young¬ 
sters in a nest, but only two, and of these two, one is invariably larger 
than the other to the extent of two-thirds, when they are quite blind 
and without the vestige of a feather. When the chick is half- 
fledged its dead brother or sister may be found in a mummified condi¬ 
tion underneath it. This shows that it does not act like the young 
cuckoo by ejecting its fellows, but, either by being stronger at birth 
it manages to obtain the greater portion of the food brought to the 
nest, or else the parent birds deliberately feed the stronger at the 
expense of the weaker, in consequence of their difficulty in obtaining 
food. Whether this be the case I cannot satisfactorily determine, 
and further observations are needed. I am, however, inclined to 
the latter view, as we find in the case of other birds that the young 
are fed in rotation, and are, generally speaking, equally robust. 
N. MANDERS, 
Colombo, August 10, 1909. Lieut.-Col., R.A.M.C. 
3. Pugnacity of the Drongo .—The drongos have earned for them¬ 
selves the name of 4 ‘King Crow ” from their habit of pertinaciously 
attacking and driving off crows and other birds many times larger 
and more powerful than themselves. This habit is of very common 
observation ; but I have to-day witnessed, for the first time, the 
