161 



13 



attributable to certain climatal causes, as is the case with the different varieties of Cuculus tenuirostris." 

 Again, in 'The Ibis' for 1863 (p. 274), he continues: — "In Formosa you find P. manillensis, as it is generally 

 known, with blue upper plumage and breast and red belly. In all my numerous specimens the colours are 

 always uniform. But in Amoy the red belly is by no means constant ; I have several skins entirely blue, and 

 others again with all proportions of red and blue. This, however, does not seem to be the case with the 

 Formosan bird ; so we will not here discuss the validity of the species/' As in the preceding paragraph 

 reference is made to the species in Formosa, we need here only confine ourselves to the consideration of the 

 bird from the mainland. First, we have two specimens from Tientsin, contained in Lord Walden's collection. 

 One is a bird in spotted dress, the other is in full blue-and-red plumage, apparently killed in the late spring or 

 early summer ; for it has no trace of the dusky shade of winter, and has only slight remains of the mottled 

 immature plumage on the centre of the throat and upper breast. The red belly is crossed with indistinct 

 barrings of blackish, with a dull white edging, and on some of these bars a slight blue shade is observable in 

 certain lights. They measure : — Total length 8'0-8 - 7 inches, culmen TO, wing 4 - 4-4 - 7, tail 3"0-3'2, tarsus l'l. 

 Mr. Swinhoe's well-known energy has provided us with a good series of skins from the neighbourhood of 

 Amoy j and through the kindness of that gentleman we have examined all the skins in his own collection, and 

 at the same time other friends have placed at our disposal several skius from this same locality. The seventeen 

 specimens now before us form a complete guide to the history of the species. Beginning with the nestling, 

 which we have fully described at the opeuing of the present discussion, we have also several in spotted plumage. 

 Then we have, in the collection of Messrs. Salvin and Godman, one in blue-and-red livery, with remains of 

 spotted plumage on the throat and breast (as in Lord Walden's Tientsin example); afterwards a male in 

 Mr. Swinhoe's collection entirely blue, excepting the centre of the belly, which is faded chestnut, everywhere 

 tinged with blue ; the under wing-coverts are also fast becoming blue, but there is no change in the under 

 tail-coverts, which are deeper chestnut, apparently not faded like the colour of the abdomen. The change 

 from a red to a blue belly is evidently a gradual operation, and the under tail-coverts are the last part to 

 succumb : thus the next specimen is blue all over, except these last-mentioned feathers, which are, however, 

 about to become blue. Thence we have every gradation of blue on these parts, the rufous gradually becoming 

 less and less till at last we have one all over blue, excepting the slightest tinge of rufous on one of the under 

 tail-coverts. Even when the bird is finally mature it seems to go every year into a winter plumage exactly 

 similar to that of its European congener, so that when in entire blue dress it is almost impossible to distinguish 

 the two species. The birds in spotted dress measure as follows : — Total length 7"5-8 - 4 inches, culmen 0'95-rO, 

 wing 4 - 45-4 - 7, tail 3-1-35, tarsus 1-1-L15; the more mature birds as follows: — Total length 7-8-9*0 inches, 

 culmen 0-9-LO, wing 4-5-4-9, tail 3"l-3-5, tarsus 1-05-1-2. 



Japan. Lord Walden has kindly lent us the three specimens procured by Mr. Whitely at Hakodadi (c/. 

 Ibis, 1867, p. 199), which are now in his possession. They are all males, and in very brilliant plumage, appa- 

 rently brighter than any we have seen yet. One of them has remains of mottled plumage on the breast and 

 of slight edgings on the head. Messrs. Salvin and Godman also possess a skin, received by them in exchange 

 from the Leiden Museum ; but this does not look so brilliant as Lord Walden's specimens, owing probably to 

 its being in partial winter plumage; traces of blue are appearing among the red of the abdomen. These 

 mature birds measure: — Total length 8-4-9'0 inches, culmen l-0-l'l, wing 4 - 7— 4 - 95, tail 3-2-3'7, tarsus 1/2. 

 Our friend Mr. Robert Bergman procured a young bird at Nagasaki on the 1st of February, 1870, which is 

 also now in Lord Walden's collection. It does not differ conspicuously in plumage from Chinese examples of 

 the same age, and measures as follows: — Total length 8 - 6 inches, culmen l'l, wing 4 - 7, tail 3 - 5, tarsus 1\2. 

 The date at which this specimen was procured seems to indicate that the bird does not migrate from Japan; 

 and, taking at the same time into consideration the exceptional brilliancy of the old birds, as well as their 

 decidedly longer tarsus, which measures 1*2 inch in both old and young birds, it is possible that the Blue 

 Rock-Thrush of Japan may yet turn out to be a different species. 



