160 ILLUSTRATIONS OF THE BOTANY OF [Simarubee. 
able uniformity in the vegetation, not only as to the principal natural orders and genera, 
but even to a considerable extent in the species of which it consists;” and we may 
consequently have an agreement with the flora of India over nearly the same extent: as 
‘we may see by a reference to the flora of Senegal, which Mr. Brown, no doubt, had in 
view. If we examine the first volume of the Flora Senegambie,—in which, following 
the series in De Candolle’s Prodromus, forty-five families are treated of, from Ranun- 
culacee to Myrtacee,—there are only three of which species are not found in the plains 
of India. Of these, Frankeniacee belongs to the flora of the Mediterranean region ; 
and of Geraniacee and Simarubee there are species at the foot of the mountains in 
India. The families consist of 157 genera, of which only forty-six are not found in 
India: a number which might-probably be reduced, if we had leisure to examine the 
extent of some of the new genera. Among the species, also, in addition to those enu- 
merated by Mr. Brown, there are several found equally in India; of these some 
probably have been introduced, while the cultivated grains are nearly the same as those 
of India. | 
Mr. Brown remarks, that there is a certain degree of resemblance between the 
vegetation of the banks of the Congo and that of Madagascar, and the isles of France 
and Bourbon ; that the flora of the east coast of Africa is little known; while with that 
of Abyssinia there was little affinity, though some characteristics of Southern Africa 
have been found, as Protea abyssinica, Pelargonium abyssinicum, and Geisorhiza abys- 
sinica, but ‘‘to the flora of Egypt that of Congo has still less relation, either in the | 
number or proportion of its natural families.” 
It has been observed, that owing to the great uniformity of temperature over a 
great extent of Indian territory, many of the same plants spread from the southern to 
the most northern parts of the plains of India, so that we have many Peninsular plants 
extending north even as far as Delhi, where also it was observed (p. 6) there is an 
approximation to the flora of Egypt, as well as’ to that of the south of Europe. On 
consideration, it does not appear remarkable, that the western side of the great 
Gangetic valley should approximate in its flora to that of Egypt, for Cairo and 
Saharunpore are situated nearly in 30° of N. latitude, whence both India and Egypt 
stretch southwards; but the Ganges flowing in the same direction, becomes tropical 
towards its delta, while the Nile, from its northern “course, becomes more European 
in its flora the nearer we approach its mouth. Both rivers, or their branches, in the 
upper part of their course, traverse or touch upon the desert, which every where crosses 
Asia and Africa in that belt where the sun’s rays, not attempered by the influence of 
the tropical rains, have the greatest power in drying up the parched and barren 
soil. In India the desert is found between the Aravalli Mountains, the Jumna, and 
the Indus; and in Egypt every where beyond the valley of the Nile. From near 
coincidence in latitude, there is great similarity between the temperature at Saha- 
runpore and at Cairo; but in Egypt, lying open to the Mediterranean, the heat is 
attempered, which in Saharunpore, from its inland situation, would become more 
excessive 
