286 SPOLIA ZEYLANICA. 
breed with us, leaving about 120 species to be accounted for 
between the regular migrants and the stragglers. The above 
figures are rough calculations based on our present knowledge, 
which is in many cases by no means perfect. So much work 
remains to be done with regard to the oology and distribution 
of our birds that the figures may need some revision when our 
information is more complete. 
Now these 240 species which breed in Ceylon may be either 
wholly ‘‘ permanent residents” or ‘partial migrants.” 
‘Partial migrants’ are those species in which some indi- 
viduals reside with us all the year round, while others migrate 
usually to regions not very faraway. Our knowledge of local 
seasonal movements is so incomplete that in many cases it is 
extremely hard to say with any certainty whether a species is 
wholly resident or only partly so. 
On the one hand, we know that in the tropics birds are 
much less given to wander than in temperate climates. 
This is forcibly illustrated by the much greater part borne 
by geographical isolation in the evolution of peculiar species 
in Ceylon as compared with the British Isles. In Britain 
there is only one well-defined species peculiar to the country— 
the Red Grouse, Lagopus scoticus—though it has been 
ascertained, largely as the result of studies in migration, that 
there are various insular races, or resident sub-species, even 
among the partial migrants. In Ceylon, which lies about as 
near to India as England lies to the Continent of Europe, we 
have over 40 peculiar species. Legge mentions 47 such, but 
one or two of these—e.g., Legge’s Hawk Eagle, Spizetus 
kelaarti—have since been discovered in South India, and 
several others might now be classed as only sub-species. ‘The 
number of insular races or sub-species is probably very high. 
Mr. Stuart Baker, who has been working out the races and 
sub-species of a good many Indian birds, tells me that, in his 
opinion, two out of every three of our residents will turn out to 
be more or less sub-specifically distinct. 
On the other hand, we know that, as a rule, in the case of 
partial migrants, the migrant individuals do not make a very 
extended journey, and India does not lie far away. It is 
very obvious to any one who is acquainted with the birds of 
