150 NATURAL HISTORY. 



up large quantities of the smaller algae for food. They are not averse to 

 decaying animal food, and in confinement when one of their number dies, 

 all the fleshy portions are quickly devoured. I have fed them on moistened 

 cracker, and they lived on it for months. 



Once one of the old sea-captains of New England was amusing himself 

 and me by relating the many marvels he had seen in all parts of the 

 world. Some of his stories were not very marvellous, and yet I know 

 th.it the imagination entered at least largely into them. At last he 

 told one so strange that he thought I would doubt it, and yet I could 

 vouch for its accuracy. In the clays of the discovery of gold in Cali- 

 fornia, lie was taken sick while crossing 'the isthmus,' and was kindly 

 nursed by an old negro woman. One day she said : " This is the week 

 when the crabs go to the sea " ; and sure enough, on the very next day the 

 woods and the fields were filled with large, rapidly moving crabs, all trav- 

 elling as fast as possible to the shore. What it meant or where they came 

 from the old sailor was unable to say; but I told him that not only on the 

 Isthmus of Panama, but in the West India Islands, there were several 

 different kinds of land-crabs which spent their whole life in the woods and 

 mountains, going only once a year to the ocean for reproductive purposes, 

 and devastating the fields through which they pass. With these forms, 

 the highest of the group, we leave the series of decapods. 



As a transition between the decapods and the fourteen-footed Crustacea, 

 may be mentioned the curious mantis-shrimps of the warmer seas. Their 

 bodies are rather weakly put together ; but their colors are unusually 

 bright and gay. They live burrowing lives on muddy bottoms or amongst 

 the coral sand, and unlike most crustaceans they deposit their eggs on the 

 sea-bottom instead of carrying them about with them. To the anatomist 

 and embryologist they afford many interesting features; but so little is 

 known of their habits that they interest others only by their bizarre shapes. 

 With the sharp spines on their claws they can inflict rather 

 severe wounds, while the tip of the abdomen is also used as 

 an organ of offence and defence. 



In comparison with the decapods in size, numbers, and 

 interest, the fourteen-footed crustaceans occupy an inferior 

 position. Possibly the most familiar of them are the terres- 

 trial sow-bugs, which swarm in moist earth, in the woods, in 

 gardens, and in cellars. They are not especially interesting, 

 bug [porcei- but they have their value in that they feed on decaying vege- 

 table matter, thus consuming much which might otherwise 

 become offensive. Like most of the Crustacea they breathe by means of 

 gills, which are shut in by folding-doors beneath the tip of the abdomen. 



