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
Kambei Mori Kambei Mori Kambei Mori or , also known as Mōri Kambei Shigeyoshi , was a Japanese mathematician in the Edo period. Some 16th-century sources suggest that Mori studied in China, but such claims are inconclusive or rejected by historians. What is known with certainty is that he started a school in Kyoto and he wrote several influential and widely discussed books which dealt with arithmetic and the use of the abacus. One of his students was Yoshida Mitsuyoshi the author of "Jinkōki," which is the oldest extant Japanese mathematical text. In a statistical overview derived from writings by and about