204 PROGRESS OF MICROSCOPICAL SCIENCE. 



tant point. At any rate tlicrc shoiild bo a close time on the coast of 

 New England, during April and May, and October and November. 

 Persons should also be fined heavily for selling lobsters with eggs 

 attached. 



He divides the larval condition of the lobster into three stages. 

 The first is a little under a third of au inch long, and was found early 

 in July at Wood's Hole, Mass. In the second stage, the animal has 

 increased in size, and rudimentary appendages have appeared upon 

 the second to the fifth segments of the abdomen. In the thii-d stage 

 the animal is about half an inch long, and has begun to lose its Mysis- 

 like (Scliizopodal) appearance, and to assume some of the features of 

 . the adult. 



There are probably two succeeding stages before the adult form is 

 attained ; one is described by our author, while the first of the two he 

 sui^poses to have existed, but has not yet discovered. After this the 

 animal ceases to swim on the surface, and late in summer seeks the 

 bottom. They feed on the young of various animals, the larvaa of 

 their Crustacea, and when much crow^led in captivity, on one another, 

 the stronger devoi;ring the weaker. In the first stage of the adult 

 form, when the animal is about three-fifths of an inch long, it still 

 difters from the adult so much that it w'ould be regarded as a distinct 

 genus, " In this stage, the young lobsters swim very rapidly by 

 means of the abdominal legs, and dart backwards, when disturbed, \\'ith 

 the caudal appendages, frequently jumping out of the water in this 

 way like shrimp, which their movements in the water much resemble. 

 Thoy appear to live a large part of the time at the surface, as in the 

 earlier stages, and were often seen swimming about among other 

 surface animals. They were frequently taken from the 8th to the 

 28th of July, and very likely occur much later." Mr. Smith thinks 

 the young pass thi-ough all the stages he describes in the course of a 

 single season. Those in the last stage mentioned he believes had not 

 been hatched from the eggs more than six weeks, and very likely a 

 shorter time. How long the young retain their free swimming habit 

 after arriving at the lobster-like form, was not ascertained. 



Specimens three inches in length have acquired nearly all the 

 characters of the adult. The descriptions of the difierent stages arc 

 very detailed, and accompanied by admirable figures. 



" Of all the larval stages of other genera of Crustacea of which 

 I have seen figures or descriptions, there are none which are closely 

 allied to the early stages of the lobster. Astacus, according to Rathke, 

 leaves the egg in a form closely resembling the adult, the cephalo- 

 thoracic legs having no exopodal branches, and the abdominal legs 

 being already developed. Of the early stages of the numerous other 

 genera of Astacidea and Thalassinidea scarcely anything is known, 

 but as far as is known, none of them appear to approach the larvfe of 

 the lobster. Most of the species of Crangonidie and Pala^mouida) 

 (among the most typical of Macrouraus), of which the development is 

 known, are hatched from the egg in the zoea stage, in which the five 

 posterior pairs of cephalothoracic appendages, or decapodal legs, are 

 wholly wanting, as arc also the abdominal legs, while the two anterior 



