Herrick[128] gives some interesting particulars with regard to the life-history of the American species. The largest recorded specimen weighed about twenty-five pounds, and measured twenty inches from rostrum to tail; similar European specimens have been recorded, but, on the average, they are not so large as the American forms. The Lobster, like all Crustacea, undergoes a series of moults as the result of increase in size, shedding the whole of the external integument in one piece. This is accomplished by a split taking place on the dorsal surface at the junction of thorax and abdomen; through the slit so formed the Lobster retracts first his thorax with all the limbs, and then his abdomen. When first issuing from the old shell the animal’s integument is soft and pulpy, but the increase in size of the body is already manifest; this increase per moult, which is approximately the same in young and adult animals, varies from 13 to 15 per cent of the animal’s length. According to this computation, a Lobster 2 inches long has moulted fourteen times, 5 inches twenty times, and 10 inches twenty-five times, and it may be roughly estimated that a 10–inch Lobster is four years old. Young Lobsters probably moult twice a year, and so do adult males, but females only moult once a year soon after the young are hatched out. The process of moulting or ecdysis is an exceedingly dangerous one to the Lobster and to Crustacea in general, and is very frequently fatal. There is, first of all, the danger of the act not being accomplished skilfully, when death always ensues. The Lobster remains soft and unprotected for about six weeks after the ecdysis, and is very apt to fall a prey to the predaceous fish, such as Sharks, Skates, Cod, etc., which feed upon it. There are, however, some peculiar adaptations connected with the process which are of interest. In order to facilitate the ecdysis, areas of absorption are formed upon the dorsal and ventral surfaces of the carapace, on the narrower parts of the chelipedes, and at other places; in these areas the calcium carbonate is absorbed, and the old shell becomes elastic and thin, so as to allow a more easy escape for the moulting Lobster. It has been noticed that while this is taking place large concretions of calcium carbonate are formed at the sides of the stomach, known as “gastroliths,” which perhaps represent the waste lime that has been abstracted from the areas of absorption. After moulting the Lobster is in great need of lime for stiffening his shell, and it has been noticed that on these occasions he is very greedy of this substance, even devouring his own cast-off skin.