LESSER WHITETHROAT. 411 



The Lesser Whitethroat has the most extensive range of any member of 

 this genus, breeding in the Palsearctic region, from the Atlantic to the 

 Pacific. In such a large range it is not to be wondered at that the bird is 

 subject to considerable variation. This is an excellent example of a species 

 breaking up into four species. Typical examples of each present excellent 

 characters, and have fairly well-deiined geographical limits. Unfortu- 

 nately, however, for the student who is anxious to define his species with 

 greater accuracy than Nature has hitherto succeeded in accomplishing the 

 task, intermediate forms occur, and individuals do not always recognize 

 their geographical limits as well-behaved species ought to do. As Hume 

 very justly observes, this is a case in which some ornithologists will treat 

 the birds as four species, whilst others will only consider them four 

 races of one somewhat variable species. I prefer to treat them as sub- 

 species, adopting the provisional hypothesis that the intermediate forms are 

 the result of the interbreeding of the several races where their geo- 

 graphical ranges meet. 



The European or typical form of the Lesser Whitethroat breeds through- 

 out Europe, Asia Minor, and Palestine, extending northwards somewhat 

 beyond the arctic circle, but not quite to the limit of forest-growth. In 

 South Europe it is principally known as a summer visitor ; but Mr. 

 Howard Saunders states that it remains during the winter in South Spain. 

 It certainly winters in the southern portions of North Africa, in the oases 

 of the desert. Nubia and Abyssinia, &c. 



In the valley of the Lower Volga, North Persia, Turkestan, the whole 

 of Siberia up to lat. 67°, and North-east China, the Siberian form of the 

 Lesser Whitethroat, S. cinerea, var. affinis, occurs in summer, wintering 

 in Baluchistan, the whole of India, and Ceylon. This form only differs 

 from the typical species in having the second primary intermediate in 

 length between the sixth and seventh, in rare instances between the 

 seventh and eighth (in the European species the second primary is inter- 

 mediate in length between the fifth and sixth) . It also differs very mate- 

 rially in its song, apparently having forgotten or never learnt the trill 

 which its European ally constantly introduces. 



In the Himalayas the Lesser Whitethroat differs from the European 

 form in having the upper parts an almost uniform bluish grey, the back 

 being scarcely suffused with brown at all. In its wing-formula it agrees 

 with the Siberian form, but is, on an average, larger than either of the 

 two forms hitherto mentioned, the length of wing varying from 2'8 to 2'55 

 inch instead of from 2'65 to 2'45. Hume named this form S. althea. It 

 breeds abundantly in the extreme north-west of Cashmere, and winters in 

 the North-west Provinces of India. 



The fourth form of the Lesser Whitethroat, to which Hume gave the 

 name of S. minuscula, is a small desert race differing from its near allies in 



