CORALS. 



(Fig. 41, i), they are of a very complex character, and are pro- 

 vided near their tips and at their sides with minute suckers, with 

 which they are enabled to grasp their prey. 



FIG. 41. ANIMAL FLOWERS, i. Actinia alcyonoides ; 2. A. gctmnacca. 



In common with the Hydrozoa, the Actiniae are furnished with 

 an armature of oblong, transparent vesicles, which have the power 

 of shooting out a long thread-like lasso of excessive tenuity. 

 These abound on the tentacles ; but there are also certain special 

 organs upon which they are crowded to an extraordinary degree, 

 and which seem to be simply magazines of these weapons. Certain 

 species of Actiniae have the faculty of emitting, from small orifices 

 scattered over the surface of the body, slender white filaments in 

 great profusion, coiled up so as to resemble tangles of sewing- 

 cotton. The slightest touch is sometimes sufficient to make these 

 filaments shoot forth from various points with great force and 

 rapidity. They have a strongly adhesive power, which is de- 

 pendent upon a very wonderful mechanism. On being examined 

 with a microscope, the entire surface of the tentacula and the 

 cotton-like threads are seen to be densely crowded with transpa- 

 rent oval vesicles, in each of which is coiled up a delicate filament, 

 often thirty or forty times longer than the capsule which contains 

 it, and moreover this lasso-thread is variously armed with sharp 



