168 



THE YOUNG NATURALIST. 



one, containing less than a pint and a half of sea water, seven freckled gobies 

 [Gohius minutus), of which two were about full grown three others about 

 half-grown and two were small ones. Besides these there were a quantity 

 of shrimps, the exact number of which I do not know, but two were of large 

 size and one very large. They lived in this aquarium, a very shallow one 

 and so with a comparatively large surface of water, a long time without any 

 seaweed at all excepting a very small portion of rock joint- wort [Conferva 

 rupestris), and the only casualty I had during the first months was the loss 

 of one shrimp, which the gobies killed when it had changed its skin and was 

 consequently soft and helpless. 



We see numbers of shore crabs (Carcinas mcenas) running about both little 

 and big. The life-history of these crabs and indeed of all the crab kind is 

 very interesting. In its earliest stage it is of course an egg, and is carried 

 about by the mother crab (I think very nearly a month but am not quite 

 sure, as the female crabs are of a very tender constitution at the. breeding 

 season and it is not easy to keep them alive then in an ordinary aquarium.) 

 When the young crab first emerges from the egg it is of a very singular form 

 and totally unlike a crab. It swims about actively while in this larval stage, 

 but, after a time, another change takes place, and the immature crustacean is 

 still microscopic and very unlike a crab, but not much unlike a lobster. The 

 zoea or larval stage of the crab was possessed of a long and prominent beak 

 and a singularly shaped ridge on the beak, both these have vanished and the 

 embryo crab is furnished with a symmetrical carapace and a straight jointed 

 tail. The limbs are a pair of hairy claws in the anterior part of the body 

 and eight swimming legs set very backward. A long sharp beak, but differ- 

 ent to that possessed by the crab in its previous stage, projects between the 

 eyes, which latter are set on footstalks. On each side of the beak are the 

 antennse. The size of the embryo crab in this stage is somewhat less than 

 one of the capital letters on this page. 



At length the young Carcinas mcenas assumes a crab-like form although 

 it is at first very small, more like a little spider than anything else. It is 

 now very active, constantly running about after food and spending a good 

 deal of its time out of the water. These tiny crabs are very fond of conceal- 

 ing themselves among seaweeds and carefully avoid their larger companions 

 who would not hesitate to make a meal of them. 



1 have had crabs in my aquaria throughout the whole of their lives. These 

 tiny crabs are very voracious after food, and I feed them on tiny pieces of 

 scraped meat. If fed regularly every day they moult again in about a month 

 (in summer time that is). For some days before they exuviate they refuse 

 food and hide up. If there be sand in the aquarium they bury themselves 



