The Descent of Man

y some remarkable facts recorded by Mr.
Blyth (5. See his admirable paper in the 'Journal
of the Asiatic Soc. of Bengal,' vol. xix. 1850, p.
223; see also Jerdon, 'Birds of India,' vol. i. introduction,
p. xxix. In regard to Tanysiptera,
Prof. Schlegel told Mr. Blyth that he could distinguish
several distinct races, solely by comparing
the adult males.), with respect to closelyallied
species which represent each other in
distinct countries. For with several of these representative
species the adult males have undergone
a certain amount of change and can be
distinguished; the females and the young from
the distinct countries being indistinguishable,
and therefore absolutely unchanged. This is the
case with certain Indian chats (Thamnobia),
with certain honey-suckers (Nectarinia), shrikes
(Tephrodornis), certain kingfishers (Tanysiptera),
Kalij pheasants (Gallophasis), and treepartridges
(Arboricola).