94 SOME WONDEKS OF THE SEA. 



Although the filament is not thicker than an ordinary 

 spider's thread, it is seen to be studded throughout its 

 length with little oval cells, or capsules, looking like 

 very transparent white grapes. Now, take an object 

 glass of considerable power, not less than half-inch, and 

 examine a single cell. 



Here I may mention that throughout this short history 

 of the Medusae, I spare the reader a mass of scientific 

 terms, certainly very imposing in appearance, but con- 

 veying very few ideas. So I shall lay aside " cnidse," 

 " ecthorase," " nematocysts," &c., which are the short- 

 hand, so to speak, of zoology, and employ their equiva- 

 lents in English. They are invaluable to science, because 

 they can be introduced unchanged into any language, 

 and I shall employ such terms as " poison- threads/ 

 " thread-cells," and so forth. 



On examining a single cell, its surface appears to be 

 crossed and re- crossed with extremely fine lines of a 

 slightly darker colour than the body of the cell. A 

 careful manipulation of the light and delicate focussing 

 will show that this appearance is caused by a very fine 

 thread coiled up within the cell. Around the base of 

 the cell is a series of tiny booklets, which remind the 

 entomologists of the beautiful hook-rows which are found 

 in the wings of bees, wasps, ants, and other insects 

 belonging to the same order. 



Here, then, is the poison apparatus, and the mode of 

 its action is as follows. 



As soon as one of these cells touches any object, the 



