BIRDS OF INDIA DEWAE. 629 



which the various forms are subjected. Unfortunately for this hy- 

 pothesis, there is evidence which seems to disprove it. For example, 

 the common house-sparrow in India differs from our English spar- 

 rows in having white cheeks, but those Indian sparrows which are 

 brought to this country do not lose the white cheek patch as they 

 should do had it been the result of the direct action of the climate in 

 India. 



THE EED TURTLE D0\T:. 



The red turtle dove {Oenopopelia t7'anquebarica) is another Indian 

 bird of great interest to the biologist. It is widely distributed over 

 the plains, and undergoes local migration. Its nesting and feeding 

 habits are identical with those of the other doves common in India — 

 the ring, the spotted, and the little brown dove. But, while in these 

 sj^ecies the cocks and the hens are alike in external appearance, the 

 red turtle dove displays considerable sexual dimoriDhism. So great is 

 the difference between the cock and the hen that they have been mis- 

 taken for different species. Thus we have in India, living side by 

 side, four widely distributed species of dove, all having similar habits, 

 and in three of these species the sexes are alike in appearance, while 

 in the fourth they display considerable differences. Why this should 

 be so, no neo-Darwinian has attempted to explain. Facts such as 

 these seem to be left severely alone by Weismann and his followers. 



SO-CALLED MIMICRY. 



The avifauna of India furnishes zoologists with what some, at any 

 rate, of them are pleased to term a most striking case of mimicry. 

 Among birds and beasts certain species have their doubles. Now, 

 when two species, which are not near blood relations, are alike in ap- 

 pearance, and this likeness appears to be advantageous to one of the 

 two species, this latter is said in biological parlance, to mimic the 

 other. Such mimicry is, of course, unconscious. It is commonly 

 supposed to have been brought about by natural selection. Now, 

 there is in India a cuckoo — the drongo-cuckoo {Surniculus lugu- 

 hris) — which resembles in appearance the common king-crow (Z>^- 

 crurus ater). Further, the cuckoo is parasitic on the king-crow. This 

 last is, as we have seen, a very pugnacious bird, especially at the nest- 

 ing season. It guards its nursery with great ferocity. I have 

 watched a pair of these little birds attack and drive away a monkey 

 which tried to climb into the tree in which their nest was placed. In- 

 deed, so able a fighter is the king-crow that some other birds, notably 

 orioles and doves, which also are very pugnacious, frequently build 

 their nests in the same trees as the king-crow, in order to share the 

 benefit of his prowess. It would be almost impossible to deposit eggs 

 in the nest of a bird so pugnacious as the king-crow without resorting 



