AMPHIPODA. 219 



The importance of these Crustaceans in the 

 economy of Nature is very great making up for 

 the smallness of their size by the immense numbers 

 in which they exist, and the ubiquity of their pre- 

 sence. They are ready at the first moment to seize 

 upon the dead matter that constitutes their ordinary 

 food, and thus to act their part as scavengers of the 

 ocean without the least delay, whilst in their turn 

 they furnish an abundance of excellent nourishment 

 to fishes and other aquatic animals. To this order 

 belong 



The Sand-hoppers* (Gammarus). These animals may be seen in 

 abundance by the seaside in summer-time, where they carry on a 

 continual warfare against the annelidans of all sorts, found on the 

 shore. Nothing is more curious than to see them, when the tide is 

 coming in, congregated in myriads, beating the sand in all directions 

 in search of their victims. No sooner do they meet with one of their 

 favourite worms, than they attack it, and although it may be ten 

 times their own size, soon kill and devour it. They never leave off 

 this work of butchery till they have fairly gone over all the mud 

 upon the shore. They are equally ready to attack mollusca, fishes, 

 or even human bodies cast up upon the beach. In their turn, they 

 supply an abundant stock of food to multitudes of shore-birds and 

 fishes. 



Dr. Sutherland relates that in Davis Straits he has seen an entire 

 seal reduced to a perfect skeleton in less than two days, by Gam- 

 marus arttcus. 



It is a species of Sand-liopper (Talitrus] that is alluded to by 

 Archdeacon Paley, as exemplifying the abundance of happiness 

 bestowed on the lower animals. 

 " Walking by the seaside in a 

 calm evening upon a sandy 

 shore, with an ebbing tide, I 

 have frequently remarked the 

 appearance of a dark cloud, or 

 rather very thick mist, hanging 

 over the edge of the water, to 

 the height, perhaps, of half a 

 yard, and of the breadth of two 

 or three yards, stretching along 

 the coast as far as the eye could 

 reach, and always retiring with 

 the water. When this cloud 

 came to be examined, it proved FlG> i 6 7._ TALrrRUS -THE SAND-HOPPER. 

 to be nothing else than so much 



space filled with young shrimps, in the act of bounding into the air 

 from the shallow margin of the water, or from the wet sand. If any 

 motion of a mute animal could express delight, it was this ; if they 



* Kdjj./j.ados, kammaros, a kind of crab or shrimp. 



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