( XV ) 
RATING Vegetables. Perhaps this name might likewise be applied to those vegetables, which are natives of 
warm, southern countries, but gradually accommodate themselves to the rigorous winters of northern climates. I 
think, it was the late Mr. John Hunter w^ho first ventured to conjecture, that man himself is not incapable of be- 
coming torpid. Professor Fabricius is of the same opinion.* Nor is it at all improbable. In his internal structure, 
in the temperatiu-e of his blood, man differs in no very essential circumstances from some of those animals, which, 
in certain climates, almost constantly pass into the torpid state. 
§. XXXIII. 
It is important for our purpose, in the discussion of the question of the disappearance of birds, that many of 
those species which are believed to be migratory are annually seen on their passage ; in the spring from the south to 
the north, and in the autumn from the north to the south. Some of these passengers migrate in immense flocks, 
whilst others go and return more individually. Mr. Bartram has seen, in the autumn, large flocks of all our four 
species of Swallows, on their return southward from Pennsylvania, through Carolina, Florida, &c. and in the spring 
on their return to the northward again, f The immense migrations of the Passenger-Pigeons are well known to every 
body in this country. I have already hinted at the great flights of Fringilla tristis, Motacilla Sialis, Loxia Cur- 
virostra, Fringilla (Hemp-Bird), and Anas canadensis, which are annually observed on their passage to the 
south. X I might mention a number of other species which move in similar bodies. I shall content myself with men- 
tioning one. This is the Brown Crane of Pennant. This species is found in Mexico. It is described by Hernandez, 
who calls it, Toquilcoyotl. § They arrive in Florida and Carolina, from the south, in the months of Hebruary and 
March. The flocks, which are immense, are heard and seen very high in the air. Their phalanx is in the form of 
the letter J> . They pass over Pennsylvania, the Jersies, New-York, &c. and continue their rout as far north as Hudson's 
Bay, where they breed, and in the autumn retire to the south again. It is curious, however, that in their return, they 
do not move in the same form in which they came. They now form two or three circles intersecting each other, often 
changing the figure of the body, and forming again, as they are joined by other squadrons. Milton's description 
of the flight of the Common Crane || of the old world equally applies to our species. 
" Part loosely wing the region : part more wise, 
In common, rang'd in figure wedge their way, 
Intelligent of seasons, and set forth 
Their aery caravan, high over seas 
Flying, and over lands with mutual wing 
Easing their flight. So steers the prudent Crane 
Her annual voyage, borne on winds ; 
The air flotes as they pass, fann'd with unnumber'd plumes." 
Paradise Lost. Book VIL 425 — 432. 
§. XXXIV. 
I fear, I shall be thought to have taken up too much time in endeavouring to prove, that the greater number of 
)ur birds which disappear on the approach of winter, retire to southern and milder climates. Indeed, I am of opinion, 
:hat the migration of our birds is a fact so well established in the natural history of these animals, that it will not, in 
general, be doubted, except by those persons who are propense to doubt on every subject. In Asia, in Africa, and 
n Europe, where observations on this subject have long been made, the migration of many species has been com- 
iletely established. In our own times, it has been particularly observed that many species visit difierent countries of 
Europe in the spring, and leave them in the autumn, in the same manner as other species visit and leave us at the 
•ame seasons of the year. 
* I am sorry, that I have not now an opportunity of examining Mr. Fabricius's memoir. I speak, from memory, of his opinions ; but I hope 
do not err. 
t See Appendix I. P. 16. I See Page viii. XIII. § Pag. 44. Cap. cskiii. I Ardea Grus of Linnaeus. 
