PEKILS OF BABY-FARMING 179 



(Linn.), Eupagurus Bernhardiis (Linn.), Porcellana longi- 

 cornis (Linn.), Galathea intermedia, Lilljeborg, and Munida 

 rugosa (Fabricius). 



It will be remembered that the larval forms of Crus- 

 tacea often show not the smallest resemblance to the 

 adults, and also that it is extremely difficult to breed in 

 confinement those which pass through many transforma- 

 tions from the egg to the perfect condition. In this in- 

 terval at every moult, the shedding of the skin is attended 

 with danger. The movement, the saltness, the temperature, 

 of the water in which they are kept should correspond with 

 the conditions they would have experienced in their proper 

 marine home. When all this has been suitably cared for, 

 the supply of appropriate food must be considered, and this 

 will probably not be the same for all the stages. When 

 several specimens occupy a common nursery the more ad- 

 vanced are very apt to destroy the less forward, and the 

 creatures being as a rule very small there are risks of 

 confusions, the larvae of distinct species being perhaps 

 mistaken for the stages of one and the same species. In 

 calm weather, and, at least, in the latitude of Great 

 Britain, especially, though not exclusively, after dark in the 

 months of August and September, it is easy in many parts 

 of the sea by means of a surface-net to obtain an abundance 

 of larval forms, but there is a great difficulty in determining 

 the species and genera to which they severally belong. 

 Being minded to connect together the several stages of a 

 crustacean's life with some approach to certainty. Professor 

 Sars made a practice of carefully drawing and dissecting 

 the forms he met with, and then by comparison of a long 

 series he was able in numerous instances to assign them in 

 proper sequence to species of which the adults were alreadv 

 known. Considering the vast numbers of the Crustacea, 

 it is evident that there is valuable work to be done on these 

 lines, enough to occupy a crowd of zoologists for many 

 years to come, and the plan is available for many who have 

 no access to the constantly improving resources of the 

 modern scientific aquarium or marine biological station. 



