84 



Part second. 



they tumble about, flee and follow each other up, the impudent 

 seizures of some and the resolute defence of others during the 

 common meal invariably excite the laughter of the spectator, 

 who is often greatly surprised at the artful and calculating ways 

 of the little creatures. In these habits the Hermit-crabs rank 

 next to the true Crabs, to which we will now turn our attention. 



The long tail (abdomen) of the craw-fishes and whole class 

 of long-tailed forms is a powerful and muscular organ of locomo- 

 tion: at one stroke it carries them far through the water. But 

 it is rather a doubtful blessing to them, for in the first place they 

 can only use it to move backwards and in the second place it 

 tastes good and that is their ruin. What trouble their abdomen 

 gives to the Hermit-crabs the reader has learned, and he will 

 therefore congratulate the crabs on having been clever enough 

 to reduce this appendage to a minimum, for which reason they 

 are called Brachyura (short-tails). The abdomen of this group 

 of Decapods, of which the Shore-crab, Carcinus (fig. 136) is a well- 

 known member, has become a small round or triangular plate 

 bent in under the fore-part of the body and invisible from above. 

 The body is developed in a transverse direction and is either 

 triangular, square or round. 



The instincts of the triangular Crabs remind one of those of 

 the hermits. They delight to deck themselves out with different 

 things. Thus Maja verrucosa (tank 13) and Lissa (fig. 138) often 

 carry on their backs and legs a forest of sea-weeds and animal 

 colonies (Polyzoa, Hydroids, etc.); thus, too, the species of 

 Inachus (fig. 139) drag round on their long thin legs all kinds 

 of plants and sea-squirts. In short, as many of these animals 

 as one collects, so many different toilettes does one find. And 

 what is their use? They afford the best possible concealment 

 from enemies and from prey. For all these objects have not 

 fastened themselves on the crabs, but have been artistically placed 

 there by the crab itself — we dare hardly say intentionally, but 

 by reason of an inherited instinct which impels the animal to 

 disguise itself in this way. All triangular Crabs are exceedingly 

 slow in their movements, and dressed up in this way they re- 

 semble most closely a stone overgrown with sea-weed, especially 

 as they have the habit of remaining quite motionless when alarmed. 

 The apparatus for affixing these foreign bodies consists of a num- 

 ber of hooked bristles which are distributed all over the shell ; and 

 on these the crab deftly fastens with its claws the algas and other 

 ornaments. The Larger Spider-crab, Maja squinado (fig. 70), a 

 crab already known to the ancients, and figured on some coins, 

 even puts small stones and mussel shells on its back, but when 

 fully grown scorns all dress. Lambrus (fig. 140) departs from this 

 custom and depends more upon its large and strong claws than 

 upon concealment. 



