M. Sundevall on the Birds of Calcutta. 173 



able dissimilarities between individuals, some being white, others 

 a deep red brown, and of both varieties there are to be found 

 some with soft wavy feathers in their tail, which are often twice 

 as long as the real feathers of the tail. As I have seen no live 

 ones except the two males above-described, which had both lost 

 their long feathers, I can throw no light on this peculiarity ; but 

 that these individuals are of the same species might be proved by 

 their perfect conformity in form and dimensions ; for the above- 

 described dissimilarity in the length of their wings is not always 

 constant ; one often sees somewhat larger brown and somewhat 

 smaller white specimens. But we cannot admit a difference in 

 species without a certain difference in form. It seems most likely 

 that the brown colour is the winter plumage ; that the white co- 

 lour begins to appear about the commencement of the season of 

 propagation through an organic chemical process in the feathers : 

 the same process which so highly enhances the colour of our 

 common birds, and causes the change in the ends of the feathers 

 of a great number of them ; also that the long feathers of the tail 

 come to perfection in the third year or later, whilst the colour of 

 the bird is previously brown, after which they become white 

 with the other feathers. Both those which I shot must therefore 

 have been younger males, which in the following year would have 

 propagated for the first time, and have acquired the two long 

 feathers. The change of the colour has already been pretty well 

 proved by Levaillant, from the remarkable information he has 

 given about a number of specimens, which he received dried from 

 India, and among which were found some which were in the 

 transition state between white and red-brown. He was not how- 

 ever aware of the fact of the existence of white males, which in 

 spring-time lose the often-named ornament of the tail. Among 

 the many nearly related species from Africa, there seem to be 

 none which show similar changes of colour. 



The brown male came in an exhausted state on board our vessel 

 as she was sailing by Ceylon, about ten [Swedish] miles from the 

 coast, and therefore out of sight of land. It had been driven out 

 to sea the day before by a storm of rain and fog, which brought 

 a great many birds and insects into the sea, and of which I got 

 several. Notwithstanding its critical situation, its stomach was 

 full of insects, and it was seen to catch several of them while 

 flying. It sat a good hour in the rigging of the ship, after which 

 it displayed a few times the common habit of the Muscicapce, to 

 fly and catch an insect and return to its former place. The white 

 specimen was shot in the neighbourhood of Calcutta 14th April. 

 I pursued it a long time while it actively hastened between the 

 branches of some high thick groves in order to catch insects. It 

 did not manifest the slightest desire to walk on the branches, or 



