MIGRATION. 
kept in k fodtft all that da y. By heating the room they 
all revived ; he opened four of them, and found their fto- 
machs quite full. The main body occupied the lioufe- 
top all day, except for two hours. About half an hour 
after nine in the morning of the 23d, there was a great 
commotion, with very loud chirping; and, within a few 
minutes after, the whole multitude took their flight, in a 
direft fouth-eaft direftion, having afcended to a great 
height in the atmol'phere. He let go the birds which he 
had caught, at certain intervals, till four o’clock, and they 
all flew toward the fame quarter. 
Not only has the direftion of their flight been obferved, 
but they have alfo been found on their paflage at a great 
diftance from land. Mr. Adanfon informs us, that about 
fifty leagues from the coaft of Senegal four fwallows fet¬ 
tled upon the fhip on the 6th of Oftober; that thefe birds 
were taken; and that he knew' them to be European 
fwallows, which, he conjeftures, w'ere returning to the 
coaft of Africa. Sir Charles Wager’s authority may alfo 
be applied to : “ Returning home (fays he) in the fpring 
of the year, as I came into foundings in our channel, a 
great flock of fwallows came and fettled on all my rig¬ 
ging; every rope w'as covered, they hung on one another 
like a fwarm of bees ; the decks and carving were filled 
with them. They feemed almoft famiflied and fpent, and 
were only feathers and bones ; but, being recruited with 
a night’s reft, took their flight in the morning.” Phil. 
Tranf. vol. liii. This vaft fatigue proves that their jour¬ 
ney muft have been very great, confidering the amazing 
fiwiftnefs of thefe birds; in all probability they had crofted 
the Atlantic ocean, and were returning from the fhores 
of Senegal, or other parts of Africa ; fo that this account, 
from that moft able and honeftfeaman, confirms the later 
information of Mr. Adanfon. 
Mr. Kalm, who is an advocate for the opinion that fwal¬ 
lows lie immerfed in lakes during winter, acknowledges 
that in crofting the Atlantic from Europe a fwallow light¬ 
ed on the fliip on the 2d September, when it had palled 
only two-thirds of the ocean. Since, therefore, fwallows 
have been feen affembled in great flocks in autumn flying 
off in company towards fouthern climes, fince they have 
been found both in their paflage from Europe and re¬ 
turning again, can there be any doubt of their annual 
migration ? 
Mr. Barrington affirms that there is very great doubt, 
and that the probability lies on the other fide. He firft 
endeavours to invalidate Mr. Adanfon’s celebrated ob- 
fervation with refpeft to the migration of the fwallow, 
and which has been confidered by many as perfeftly de- 
cifive of the queftion. He endeavours to fnow, that the 
four fwallows which that naturalift caught, on their fet¬ 
tling upon his fltip, on the 6th of October, fifty leagues 
from the coaft of Senegal, and which he fuppoles to have 
been then proceeding from Europe to pafs the winter in 
Africa, could not have been true European fwallows; 
or, if they were, could not have been on their return from 
Europe to Africa. His objections are founded princi¬ 
pally on fome proofs which he produces of M. Adanfon’s 
want of accuracy on this fubjeft, which has led him, in 
the prefent inftance, to miftake two African fpecies of the 
fwallow-tribe, deferibed and engraved by Brilion, for Eu¬ 
ropean fwallows, to which they bear a general refem- 
blance; or, granting even that they were European lwal- 
lows, he contends that they were flitting from the Cape 
de Verd illands on the coaft of Africa; “to which ffiort 
flight, however, they w'ere unequal, and accordingly fell 
into the failors’ hands.” 
M. Vaillant, the celebrated traveller in Africa, wliofe 
authority muft have great weight in every thing relating 
to ornithology, is of the fame opinion with Mr. Barring¬ 
ton. He informs us, that he_found three fpecies of fwift 
in Africa, one of which only bears great refemblance to 
thofe of Europe, or is perhaps the fame; but he found 
fix fpecies of fwallow, not one of which is to be met with 
in Europe; and he is well convinced that none of our 
&>>' 
fwallows ever reach the Cape of Good Hope m their mi¬ 
grations, though Kolbe and feveral others aflert that they 
do, and Buffon has copied thefe falfe teftimonies. Al¬ 
though many fpecies of European birds occur at the 
Cape, not one of thefe, Vaillant aflerts, will be found to 
be really an individual come from Europe to the Cape, 
and afterwards to return. It is by no means certain whi¬ 
ther our migratory birds repair when they quit Europe; 
but one important point, which Vaillant wilhes to imprefs 
on the attention of naturalifts, is, that none of thofe birds 
which abandon Europe for the winter ever produce a new 
covey during their abfence; and, the fame point having 
been verified at the Cape in refpeft to birds which quit 
that place at a certain feafon, we may be allured that all 
birds produce once a-year only, in whatever climate. 
They retire or migrate for the fake of food or of climate ; 
fo that, in whatever diftant country w r e may find birds, 
fimilar to our own, laying eggs, thefe cannot be the fame 
individuals which have produced with us in the courfe of 
that year. The fwallows and martins of Africa refemble 
thofe of Europe in exterior form, and ftill more in their 
habits and modes of life ; it is not therefore to be much 
wondered at that travellers fliould aflert that they had 
met with our European birds at the Cape. 
“ All the fwallows which neftle in the parts of Africa I 
have vifited,” fays Mr. Vaillant, “ remain there during 
the fiimmer-feafon only, the time of the great heats; and 
all the fpecies which are feen there during the winter of 
that country, or the rainy feafon, (which is there called 
the bad monloon,) are fuch as come from other parts of 
Africa after having hatched their eggs; and they do not 
lay a fecond time, as I have well obferved by the fize of 
the young ones they always bring with them; and, as 
thofe who return in the fummer to make their nefts as 
before never bring any young birds with them, it is evi¬ 
dent they have not propagated during their abfence; an 
additional proof that birds do not produce at two leafons 
of the year, whether in hot countries or cold. It is alfcr 
to be obferved, that birds of paflage never arrive, in the 
country where they do not produce, during the pairing- 
feafon of that country ; it is natural therefore they fhould 
not lay eggs, fince the birds of that country do not lay 
while they are there. 
“ Another important obfervation, upon the fubjeft of 
migratory birds, is, that, while one fpecies of bird, having- 
completed its laying in one country, goes to another, 
other birds, of the Jayne fpecies, having in like manner pro¬ 
duced their young elfewhere, come into that country 
which the former had quitted; which leads to the con- 
clufion, that it is not always want of food that forces 
birds to expatriate, but the want of a change of climate. 
In Europe, where during the winter infefts are fcarce, it 
is very natural that birds which feed upon infefts ihould 
all leave us, or nearly all; yet there are fome infeft-eat- 
ing birds which vilit us and fpend the fevere feafon 
among us, contriving to find fubfiftence. But in very 
hot countries, as Africa, whence all the fwallows wdio' 
have hatched their young emigrate at the approach of the 
rainy feafon, it cannot be the want of food which caules 
them to depart, fince at that very feafon other fwallow* 
arrive which find abundance of food.” 
M. Vaillant therefore advifes to confider the birds in 
any country as diftinguilhed into three claftes : 1. the 
birds belonging to that country, and which breed there ; 
2. fojourners, who remain fome months, but not during 
the breeding-fealon ; 3. birds of paflage, which traverle 
the country, without making any ftay, and leave no pro¬ 
geny behind them. But what praftice, labour, and ob- 
iervation, are required, to be enabled to make thefe 
diftinftions ! OiJ'eaux d'Afriquc, tom. v. 
We ftiall here only add, in oppolition to the remarks 
of Mr. Barrington, the following obfervations of the Rev. 
Mr. White in a letter to Mr. Pennant on this fubjeft. 
“ We muft not (fays he) deny migration in general; 
becaule migration certainly does fubfift in lame places, as 
my 
