408 ETENIXGS AT THE MICKOSCOPE. 



I am going to bring under your notice this evening 

 some liiglily curious examples of animal weapons, of 

 wliicli the very existence was until latelv altogether 

 unsuspected ; yet so profusely distributed that they are 

 eminently cliaracteristic of the two great classes of 

 animals we have been recently considering — viz., the 

 JMedusjB and tlie Zoophytes. They liave repeatedly 

 fallen under our observation in examining the speci- 

 mens of these creatures which we liad selected, bat I 

 had reserved the fuller elucidation of them for an occa- 

 sion in which they should come before us under cir- 

 cumstances of such unusual development as greatly to 

 facilitate our researches. The weapons I speak of are 

 the cnid(B or nettlin2:-cells. 



Look at this beautiful Scarlet-fringed Anemone 

 {Sagarta mzniata), expanding to the utmost its disk 

 and tentacles in the clear water of the tank. I touch 

 its bod}^ ; instantly the blossom-like display is with- 

 drawn ; the column closing over it in the form of 

 a hemispherical button, M-liich goes on contracfing 

 spasmodically. At the same time sec these white 

 threads which shoot out from various points of the 

 surface ; new ones appearing at every fresh contrac- 

 tion, and streaming oat to a length of several inches — 

 resembling in appearance fine sewing cotton, twisted 

 and tano^led irreq-ularlv. 



Kow the animal has attained its utmost contraction, 

 and the threads lengthen no more. But already they 

 are disappearing; each is returning into the body by 

 the orifice at which it issued. It is, as you may see 

 bv examining^ it carefullv with a lens, ffradually con- 

 tracting into small irregular coils, at that end which is 

 attached to the animal ; and these little coils are, one 



