METACARPUS—MIGRATION 547 
middles,” while in the other division, ACRoMyYoDI, the syringeal 
muscles are attached to their extremities. Garrod further 
divided the Mesomyodi into HOM@oMERI, comprehending 'TRACHEO- 
PHONZ and HApPLOOPHON#, and HETEROMERI. Mesomyodian 
Families are most characteristic of the Neotropical Region, all but 
three, Pittidx, Philepittide and Acanthidosittidx, being, so far as is 
known, peculiar to the New World. 
METACALRPUS, generally used in Ornithology for the portion 
of the wing from the wrist (CARPUS) to the root of the fingers, but 
since the distal carpal bones coalesce with the proximal end of the 
metacarpals, this part should strictly be called carpo-metacarpus 
(see Hand under SKELETON). 
METATARSUS, by Ornithologists often applied to that part 
of the foot which reaches from the ankle-joint to the root of the 
toes and is commonly but wrongly called the Tarsus; the distal 
tarsal bones coalescing with the proximal end of the metatarsals 
(see Foot under SKELETON). 
MEW, Angl.-Sax. Maw, see GULL. 
MIGRATION. Strangely confounded by many writers with 
the subject of GEOGRAPHICAL DISTRIBUTION is that of Migration. 
True it is that owing to the vast powers of locomotion possessed 
by nearly all Birds, we have individuals belonging in the main 
to certain groups, but by no means always confined to them, stray- 
ing from their proper quarters and occurring in places far removed, 
not only from the land of their birth, but from the country whither 
they are ordinarily bound in their journeys, to reach which is the 
object wherefore such journeys are undertaken. It may be that 
in some measure this erraticism is governed by fixed laws, and 
indeed indication is not wanting that such laws exist, though as 
yet we know much too little to lay them down with any approach 
'to confidence. But it is obvious on reflection that granting the 
existence of most rigorous laws of this kind—determining the 
flight of every winged vagabond—they must be very different from 
those which are obeyed by Birds commonly called ‘ Migratory,” 
and year after year moving, according to a more or less fixed 
rule, from one locality to another with the seasons as they roll. 
The former laws would seem to be created or controlled by purely 
external circumstances, which if they possess any periodicity at all 
possess a periodicity of cycles, and are most likely dependent in the 
main on cycles of the weather, but on this point observation has 
not yet supplied us with the means of avoiding speculation. We 
may indeed say almost without much risk of error that so many 
individuals of a foreign species—whether North-American or Asiatic 
—will occur in Great Britain so many times in the course of a 
