Silk industry of Cheshire Peak District. Fast flowing streams forming the River Dane, River Bollin, River Dean and River Goyt provided a moist environment and potential power to drive waterwheels in mills. The coach road from Derby to Manchester passes through, or near to each of the prominent silk towns, and later in 1831 Macclesfield Canal joined Congleton, Macclesfield and Bollington to the Trent and Mersey Canal and the Midlands and the seaports. Silk is a naturally produced fibre obtained from many species of the silk moth. In 1700 the favoured silk was produced by a moth (Bombyx mori), that used it to spin
Crustacean larva (lecithotrophy). In species with normal development, eggs are roughly 1% of the size of the adult; in species with abbreviated development, and therefore more yolk in the eggs, the eggs may reach 1/9 of the adult's size. The post-larva of shrimp is called "parva", after the species "Acanthephyra parva" described by Henri Coutière, but which was later recognised as the larva of "Acanthephyra purpurea". In the marine lobsters, there are three larval stages, all similar in appearance. Freshwater crayfish embryos differ from those of other crustaceans in having 40 ectoteloblast cells, rather than around 19. The larvae show abbreviated development,