273 



THE POPULAR EDUCATOR. 



delicate creature like the moth of Bombyx mori could unassisted 

 have forced its way through a texture so immensely strong as the 

 tough and almost leather-like capsule in which it was so long 

 sealed up. Unassisted, it must as surely have perished in its 

 self-spun cell, as though locked up in some cavity of the solid 

 rook, for no moth possesses the power cf eating through such a 

 wall as that which the larvas can build. But here steps in to 

 the aid of the imprisoned insect that beautiful, wise, and 

 inscrutable Power which rules the universe and leaves nothing 

 undone. The moth throws out a fluid, or secretion, which 

 possesses the power of so softening the strong cement which 

 bound the thousands of tough silk fibres together, that by a 

 trifling effort they are thrust aside, and the little 

 moth, soft as swan-down, with closely-folded 

 wings, struggles into light and life. Could some 

 chemist discover the nature of this marvellously 

 active and potent solvent for even the horn-like 

 cocoons of the Tusseh worm in India (Anthorea 

 paphia) yield immediately to it an inestimable 

 boon would be con- 

 ferred on the wind- 

 ers of silk, whose 

 great difficulty con- 

 sists in so soften- 

 ing by artificial 

 means the silk 

 under treatment as 

 to admit of its 

 being reeled suc- 

 cessfully. 



Who shall say of 

 what fell ingredi- 

 ents the powers of 

 another description 

 of cocoon are made 

 up ? Here we al- 

 lude to the Ngwa, 

 or poison-grub of 

 the bushmen. This 

 cocoon, instead of 

 being formed from 

 silk, is built up of 

 fine earth or clay, 

 and is buried in the 

 earth. When re- 

 quired for poison- 

 ing arrows, it is 

 dug up and broken 

 open, when the 



juices exude. Should any of theso enter a 

 cut, scratch, or wound, agony of the most 

 indescribable intensity is the result, and in 

 the absence of the proper antidote, which, in 

 the form of a plant (the Cala he tel me), is 

 wisely placed by the Creator in the region 

 of this baneful pupa-case, insanity, suicide, 

 or both evils combined, would probably be 

 the fate of the sufferer. In this case it is 

 well that even Lucretia Borgia herself would have utterly failnl 

 to imitate the natural chemistry which has so fearfully endowed 

 the African poison-grub. Reasoning thus, we say, place the 

 juices of the sharp-spired murex (Fig. 1), and those of the 

 smooth and painted porcelain shell (Fig. 2), in the hands of the 

 most experienced chemist in the world, and we doubt his being 

 able to point out the spine-forming qualities of the one, or their 

 absence in the other. Therefore, we think, from the evidence 

 before us, it is, to say the least of it, probable that these land 

 and sea rock and timber borers possess the power of secreting 

 a peculiar fluid which, like that of the silkworm moth, acts in 

 a manner not to be imitated by artificial means. 



Fig. 3 in the annexed illustration (reduced view) represents 

 the common finger pholas (PJwlas daciylus), as it is seen on 

 breaking away the rock in which its tube is bored. 



T'le dentalium-tusk shell, or Hya-qua, the subject of our 

 illustration (Fig. 4), is an example of a tube-dweller bearing 

 a single shell, unprotected by a rock gallery. This shell is 

 remarkable as forming, so to speak, the connecting link between 

 the true mollusks, as represented by ordinary shell-dwellers and 



1. THE SHARP- SPIRED MUREX. 

 2. THE COWRY (CYPRJEA 

 MONETA). 3. FINGER PHOLAS 

 (PHOLAS DACTYLUS). 



the sea-worms (Annelida), examples of which are to be found on 

 almost every oyster and crab shell brought to market. 



The serpula is one of these. Both the dentalium and serpula 

 are red-blooded creatures, but nevertheless do not belong to 

 the same family. The dentalium stands, so to speak, on the 

 border-land dividing the two great and curious families, Mol- 

 lusca and Annelida. Dentalium shells of from an inch to an 

 inch and a half in length are not by any means uncommon 

 on our own coasts ; but the true dentalium of commerce, 

 the tusk-shell, or Hya-quo, is an inhabitant of warmer seas 

 than ours, and grows to a much larger size than those 

 fount! in British waters. Amongst the Indians of North- West 

 America, this shell is used as a circulating 

 medium, just as the Cowry is used by the in- 

 habitants of India and the Eastern world. The 

 commercial valuo of the dentalium is estimated 

 according to its length when threaded on a 

 string. Thus a cord of a given length which 

 will hold ten~of these shells is of less value than 

 one which will only 

 hold six; and so 

 on. The manner 

 in which the den- 

 talium is captured 

 by the Indians is 

 both ingenious and 

 curious. The habit 

 of the shell when 

 containing the liv- 

 ing mollusk is to 

 rest mouth up- 

 wards in the fine 

 deposit at the 

 bottom of the sea. 

 Bearing this in 

 mind, the crafty 

 Indian provides 

 himself with a 

 long-handled im- 

 plement, armed at 

 the end with a 

 number of sharp- 

 ened fis'i-bones. 

 Then, entering his 

 canoe, he is pad- 

 dled quietly along 

 over the spots 

 which experience 

 has shown to be 



rich in the sought-for shells. Here, by con- 

 stantly thrusting his bone-pointed spear down- 

 wards, he from tiire to time contrives to im- 

 pale one or more dentalia. The pointed fish- 

 bone, entering their open, tube-like mouths, 

 penetrates their soft tissues, and holds them 

 with sufficient firmness to admit of their being 

 drawn into the canoe and shaken off. 



The solen, or razor-fish as it is commonlj 

 called, is a bivalve shell commonly met with on nearly all 

 sandy coasts at home and abroad. (Fig. 5.) The habits of this 

 mollusk are not unlike those of the dentalium, but instead of 

 confining itself to comparatively deep water, the razor-fish is 

 found abundantly on the sand flats after the receding of the 

 tide. A small heap of newly-raised sand serves to disclose its 

 lurking-place, and a sharp-pointed and well-notched stick thrust 

 adroitly from above downwards, just as an Esquimaux spears a 

 seal in the ice, seldom fails to bring the olen to light. The 

 would-be captor who heedlessly employs bis finger in lieu of the 

 stick will, in all probability, have cause to remember the razor- 

 fish and its trenchant shells. These mollusks are in many 

 localities used extensively as bait, and are, when crisply fried 

 with bread-crumbs, a most appetising dish. There are nume- 

 rous bivalve shells, not true tube-dwellers, which bury them- 

 selves in the sand. Of these we can have little to say in the 

 present paper. There are other creatures dwelling in the 

 sands of the sea-shore, without the protection afforded by shells, 

 but a consideration of these must be reserved for a futuro 

 lesson. 



4. DENTALIUM Ml-TH SlfKLJ. 

 OR TUSK SHELL (HYA-QUA). 

 5. THE RAZOR -FISH OR 

 SOLEN. 



