62 Proceedings of ‘the British Associations 4 
—nature of sickness—inferior animals associated with man—cer- 
emonies con with marriages, births and burials—notions of 
a future state—habitations of the people—monuments—remains 
of skeletons—tools and instruaments—form of government—food 
—mode of cooking—clans or castes—laws—geographical limits 
and character of the region—population—teligious observances. 
A memoir was read on the Pollen and Vegetable impregna- 
tion; by Dr. Aldridge, of Dublin. The author having discover- 
ed that nitric and other inorganic and organic acids produce the . 
dehiscence of pollen-grains, in the same manner as if placed on 
the natural stigmatic surface, instituted experiments, of which 
the following are the general results. 1. The spore of crypto- 
gamic vegetables, which some botanists consider analogous to 
pollen, do not dehisce under the influence of acids. 2. The pol- 
len of the grasses is spherical, both when dry and when placed in 
water; with acid it bursts, protruding one long, cylindrical mass, 
which remains afterward unacted upon by the liquid. .3. The 
pollen of the Aroideze, Colchicacee, Smilacez, Liliaceze, Comme- 
linaceze, Bulomacez, Amaryllidaceze, Iridaceze and Conacex, 
are, when dry, oval, and marked with a dark neutral line ; but 
become, when placed in water, more broadly oval or circular, the 
long diameter remaining the same, and the opake line disappear- 
ing, after the addition of acid; the external membrane of the 
pollen or peripollen dehisces by a chink or suture sufficiently 
broad to permit the contents or endopollen to escape without any 
alteration in its form, after which the endopollen remains unacted 
upon by the liquid. 4. In the Salicinew, Salicarie, Legumino- 
se, Rosacez, Crassulacee, Saxifragacee, Hypericacen, Rutacez, 
Hippocastanesr, Resedacez, and the tribe Helleborez of the Ra- 
nunculacez, the pollen when dry, oval and marked with a dark 
central line, becomes when placed in water, round or nearly so, 
the dark line disappearing ; and when acted upon by acids, as- 
sumes a triangular form, and protrudes at three equidistant points 
cylindrical or club-shaped masses very similar at the origin to 
tubes, and presenting the appearance of being enveloped by 2 
membrane. 5. In the greater number of the remaining Dicoty- 
ledons examined, the hed pollen is ee and either broadly oval 
or spherical. 6. In the Ericacee and Epacridacew, the pollen 
grains when dry, appear triangular or oval in some instances, tri- 
angular or rhombic in others, according to the position in which 
ean, 
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