THE MEANS OF SELF-PROTECTION POSSESSED BY PLANTS. 985 
the crystals are produced when the plant is wounded by the teeth 
of any animal. i 
Orinum ornatum, Wight, the pretty white lily so common in the 
Concan, and known to the natives as qafdtater, has such acrid bulbs 
that they are used to blister cattle. 
Several species of Vitis protect their tubers by the same mecha- 
nical means, V. indica for example, Vitis carnosa protects its fleshy 
stems, and V. lanceolaria its fruit, whence it has received the 
Marathi name of @raitarat 4, or itch-berry-vine. 
Gnetum scandens, ¢4%t, produces a plum-hke fruit in the pulp of 
which are many stinging hairs of a reddish yellow colour. 
Hibiscus cannabinus and Sterculia urens have formidable seed 
pods beset with stinging hairs. The different species of Mucuna 
protect their pods in the same manner. I need hardly mention the 
many thorny plants found in this country, as their means of protec- 
tion is so obvious, he nettles form a separate class, their irrita- 
ting action being partly mechanical and partly chemical. The 
stinging hairs with which these plants are armed are hollow ; at the 
base of cach hair is situated a gland containing an acid (formic). 
When the hair enters the skin and is broken off, the pressure causes 
the discharge of the acid, by which a swelling is produced like that 
caused by the sting of many insects. ‘The nettle tribe is well re- 
presented in India by the Pouzolzias, Gerardinas, Boehmerias, and 
Urticas. A species of Pouzolzia is known to Europeans as the 
Nilgiri nettle, and Urtica interrupta, @aid, is a common weed in 
neglected corners of the Bombay gardens at this time of year, and 
is nob unlike the common English nettle. It may be thought that 
nettles have little worth protecting, but the genera Beehmeria and 
Pouzolzia yield some of the strongest and finest fibres in Asia. 
Many plants are protected by their poisonous secretions, notably 
those of the Euphorbiacees. Well-known examples are afforded by 
the genera Excecaria, Buphorbia, Ricinus and Croton, all contain- 
ing poisonous principles which protect their foliage and fruit from 
injury. 
The Hxeecaria Agallocha so common about Bombay derives its 
Latin name from excecare, to blind, and is called by the Marathas 
af, on account of the great swelling and pain caused by contact 
with its acrid milky juice. It is difficult to induce labourers to 
cut or interfere with the tree, so much do they dread it, and animals 
equally avoid it. This plant, although it bears the name of Agal- 
