Bald-faced hornet hydrocarbons serve as a barrier to moisture diffusion and thus prevent dehydration in wasps. Cuticular hydrocarbon profiles vary over species and nests, and so cuticular hydrocarbons are a proposed mechanism for nest-mate recognition. Worker and queen cuticular lipids have similar components, but their distributions differ dramatically, implying that cuticular hydrocarbons also play a role in caste differentiation. The following lipid profiles were determined from specimens collected in the summer and early fall of northeastern Georgia in 1989. The dominant hydrocarbons recovered from the cuticles of workers were n-alkanes and methyl branched and dimethyl branched alkanes with a C27 or a
Robert Bald of the system of apprenticeship in the West Indies. The meeting attendees included the Lord Provost and other city dignitaries, as well as those connected with the Emancipation Society. Bald is reported as seconding the first resolution against the evils of apprenticeship, which was called for the abolition of a system that was but slavery under another name. In 1808 Bald mentored Francis Benjamin Hall, civil engineer and later acted as a mentor for the teenaged James Nasmyth, engineer and inventor of the steam hammer, introducing him to noted engineers and taking him on trips to engineering sites. Nasmyth mentions