318 
DETERMINATIONS OF THE 
Species 5.— Opuiitia Dilleilii is well figured by Wight in his 
Illustrations of Indian Botany, ii, (1850), plate 114 ; and fairly well 
figured in the Botanic Register, (1817), plate 2-55. 
Species 6 . — Cereus pterogoiius is well figured in the Botanic 
Magazine, (1863), plate 5360. 
CONCLUSIONS. 
Five species of Opuntia and one of Cereus are shown to have run 
wild in India. Of them, one — Opnntia m^nacantha. Haw. — apparently 
came into India much earlier than 1786, when our records begin, possibly 
as early as 1700 : another — Haw. —apparently reached 
Southern India not later than 1750. Opuntia cochinelifera came into 
India 4n 1786. A fourth species came into India at the very end of the 
eighteenth or in the Hrst few years of the nineteenth century : it was 
Opuntia elatior. Opuntia nigricans came into India early in the 
nineteenth century. 
Being American plants they have chiefly reached India via Europe. 
Opuntia monacantha was possibly in European gardens in the sixteenth 
century ; it was certainly in English gardens before the end of the 
seventeenth century. It was established in the Cape in, and probably 
long before, 1772, as well as in India and possibly also in Cochin-China. 
Opuntia cochinelifera was in England from 1688. Opuntia Billenii 
was in English gardens from before 1732 and so was Opuntia elatior. 
Opuntia monacantha in 1795 had spread (probably from the banks 
of the Hughli) through Bengal up to Dinajpur and perhaps beyond. 
From the Madras coast, before 1800, it had spread right up to the 
centre of Mysore and probably further. 
In Northern India it has spread, before 1838, to Ludhiana in the 
Punjab ; and in 1840 Griffith noticed an Opuntia in cultivation in a 
garden in Kdfiristan which doubtless was it. 
Before 1875, possibly long before, two Opuntias,onQ probably it 
had become established in Burma, and of them, the one we are now 
dealing with, is prevalent at the present date in the dry central zone. 
The wild cochineal insect introduced into India in 1795 spread 
so rapidly on Opuntia monacantha as to destroy it, branch and root, 
out of the countryside. The insect was introduced into both Bengal 
and Madras ; but owing to the action of the Government of Madras in 
encouraging its propagation it spread more rapidly there than in 
Bengal. It had almost done its work of destruction in Southern India 
in twenty years ; but in the north it took sixty years to travel from 
