62 Proceedings of the British Association. 



■ — nature of sickness — inferior animals associated with man — cer- 

 emonies connected with marriages, births and burials — notions of 

 a future state — habitations of the people — monuments — remains 

 of skeletons — tools and instruments — form of government — food 

 — mode of cooking — clans or castes — laws — geographical limits 

 and character of the region — population — religious observances. 



A memoir was read on the Pollen and Vegeta.hle 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 Aroidese, Colchicacese, Smilacese, Liliaceae, Comme- 

 linacese, Bulomacese, Amaryllidacese, Iridaccce and Conacese, 

 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 Salicinese, SalicariEe, Legumino- 

 S9e, Rosacese, Crassulaceas, Saxifragaceee, Hypericaceas, Rutaceas, 

 Hippocastaneas, Resedaceee, and the tribe Helleboreee of the Ra- 

 nunculaceas, 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 a 

 membrane. 5. In the greater number of the remaining Dicoty- 

 ledons examined, the dry pollen is opake, and either broadly oval 

 or spherical. 6. In the Ericaceas and EpacridaceEe, the pollen 

 grains when dry, appear triangular or oval in some instances, tri- 

 angular or rhombic in others, according to the position in which 



