298 SPOLIA ZEYLANICA. 
I do not by any means pretend that I have proved my 
theory conclusively, but the facts I have stated seem to 
indicate its possibility. Our knowledge of the subject is as 
yet very imperfect. In other problems of migration we have 
for guidance a great mass of carefully sifted evidence based 
on work in other parts of the world; but here is a point 
which seems to have been comparatively unnoticed, and in 
which reliable evidence would be of great value. Such reliable 
evidence requires a large series of accurate observations and a 
patient examination of the records obtained. It is one more 
instance of the vast field of work in our Ornithology which 
still awaits investigation. 

