Bombyx mori 300 to about 900 m (1,000 to 3,000 ft) long. The fibers are very fine and lustrous, about 10 μm (0.0004 in) in diameter. About 2,000 to 3,000 cocoons are required to make a pound of silk (0.4 kg). At least 70 million pounds of raw silk are produced each year, requiring nearly 10 billion cocoons. Due to its small size and ease of culture, the silkworm has become a model organism in the study of lepidopteran and arthropod biology. Fundamental findings on pheromones, hormones, brain structures, and physiology have been made with the silkworm. One example of this was
Nicolas Mori programmes were headed by the grim device of a death's head and the legend Memento Mori. As a performer 'Mori's attitude had the grace of manly confidence. His bow arm was bold, free, and commanding, and the tone he produced was eminently firm, full, and impressive. His execution was alike marked by abundant force and fire, by extraordinary precision and prodigious facility, but lacked niceties of finish and the graces and delicacies of expression' (Quarterly Mag. Music, iii. 323). He left behind him a son, Francis Mori (1820-1873), the composer of a cantata, entitled 'Fridolin;' an operetta, with words by