THE SHELLS OF THE GULF OF CALIFORNIA. 213 



astonishing rapidity, as in the Razor shells; or to crawl slowly, as the 

 River Mussels; or to spin an anchor cable, as the true Mussels; or to 

 jump, as the Cockles." In the Borers it answers the purpose of 

 grindstone, scraper, and polisher. In Gastrochaena its comparatively 

 small size is compensated for by the freedom with which the creature 

 can move round and round in the capacious chamber. It is supported 

 by a beautiful system of muscles which are moored to the fulcrum of 

 the shell, and the nutritive material is abundantly poured into it to 

 supply the waste. Our little tunneler sets to work with all the ardor 

 of youth. His feeble finger, more delicate than any lady's, and as 

 little used to toil, handles the rough surface of his cave, presses and 

 rubs, rubs and presses, and finds the occupation as congenial to his 

 instincts as whipping a wooden horse is to a little boy. His skin 

 hardens with exercise. The invisible animalcules contribute their 

 quota of silex and cartilage. The work of life has commenced in 

 earnest. Would that we men, who have, offered to us the grandest 

 and the noblest destiny, had but one small fraction of the untiring 

 perseverance of these headless and uncared-for hermits. How often 

 we talk of drunkards and debauchees reducing themselves to the level 

 of the beasts. It is a libel on the brute creation. They fulfil their 

 mission. Even the little Gastrochaena is obedient to the will of the 

 Lord, and is the instrument to accomplish his work. It is man alone 

 that is disobedient. 



The work progresses. The terrestrial changes of day and night 

 do not reach the ocean-covered cavern. But still, in the absolute 

 darkness of that solitude, tired nature craves and finds her stated 

 intervals of repose. The Gastrochaena draws its finger-foot within its 

 mantle, like the squirrel rolling itself in its protecting tail, and goes 

 to sleep. So does the Laplander know the time of night, though the 

 unsetting sun is high above the horizon; and the spiritual world has 

 its Sabbaths of repose. 



As our bivalve wears out his tissues so fast in his hard labor, it is 

 necessary that the renewing functions of assimilation and respiration 

 should be carried forward with considerable vigor. This is provided 

 for by the long siphon pipes, already mentioned. The creature gets 

 his air and victuals from behind, while he is at work in front. Unceas- 

 ingly he finds himself surrounded, even permeated, with a nutritive 

 and cleansing atmosphere. The active muscles at the extremity of 

 the pipes are forever inducing currents in the watery medium, both 



°My friend Mr. S. Stutchbury, formerly curator of the Bristol Institution, Englaud, when 

 dredging in the Australian seas, had the good fortune to obtain the first liviug specimen 

 of TriQonia, a beautiful and remarkable tribe of animals which, after first appearing in the 

 secondary rocks, culminated in the higher oolites and cretaceous rocks, and suddenly disap- 

 peared in the tertiaries. He placed his solitary treasure on the middle of the rower's seat, 

 when suddenly the blind and apparently passive little creature opened its valves, put out its 

 leaping-pole, and in an instant, by one spring, had cleared the side of the boat and was sale in 

 its native element. Specimens may be seen in the Smithsonian Museum, obtained by Dr. 

 Stimpson. This is only one among the many indications that in the Australian regions we 

 have the last, remains of peculiar types of organic life, which in other portions of the world 

 have given place to more perfect developments. 



