BIVALVES — THEIR FOOD. 803 



bivalves furnislied with a byssus, we frequently find en- 

 tangled amid its fibres, or concealed within the valves, one 

 or more small crabs (Pinnoteres), of which the older natural- 

 ists, who never left an observation to stand, like truth, all 

 naked, but ever clothed it with some pretty vestment, tell us 

 a tale not to be passed over in this place, and which I pre- 

 sent you in the words of Dr. Philemon Holland, the labori- 

 ous translator of Pliny. " The Nacre, also called Pinufe, is 

 of the kind of shell fishes. It is alwaies found and caught 

 in muddle places, but never without a companion, which 

 they cal Pinnoter, or Pinnophylax. And it is no other but 

 a little shrimpe, or, in some places, the smallest crab, w^hich 

 beareth the Nacre companie, and waites vpon him for to get 

 some victuals. The nature of the Nacre is to gape wide, 

 and sheweth vnto the little fishes her seelie body, without 

 any eie at all. They come leaping by & by close vnto her ; 

 and seeing they havte good leavie, grow so bardie & bold, as 

 to skip into her shel and fill it ful. The shrimp lying in 

 spiall, seeing this good time & opportunitie, giueth token 

 thereof to the Nacre, secretly with a little pinch. She hatli 

 no sooner this signall, but she shuts her mouth, & whatso- 

 ever was within, crushes & kills it presently ; and then she 

 deuides the bootie with the little crab or shrimp, her senti- 

 nel] and companion. I maruell therefore so much the more 

 at them who are of opinion, that fishes and beasts in the 

 water haue no sense."* 



Of bivalves there are some which, as I have told you, 

 bore into wood and rocks ; but I need scarcely guard you 

 against entertaining the supposition that they eat the mate- 

 rial on which they work, although there are authors who 

 have attributed to them " a stone-eating power and ap- 

 petite." The Teredines, however, really eat the wood 

 destroyed by them ; for Mr. Hatchett proved the pulp in 



give a better conception of the amount of Medusse in this extent, if we 

 calculate the length of time that would be requisite, with a certain number 

 of persons, for counting this number. Allowing that one person could count 

 1,000,000 in seven days, which is barely possible, it would have required that 

 80,000 persons should have started at tlie creation of the world, to com- 

 plete the enumeration at the present time ! — What a stupendous idea 

 this fact gives of the immensity of creation, and of tlie bounty of Divine 

 Providence, in furnishing such a profusion of life in a region so remote 

 from the habitations of men ! But if the number of animals in a si^ace of 

 two miles square be so great, what must be the amount requisite for the 

 discoloration of the sea, through an extent of perhaps 20,000 or 30 000 

 square miles!" — Scoresby's Arctic Regions, i. 179. — See also Darwin's 

 Journal, iii. 14, &c. 



* Hist, of the World, i.26]. 



