406 HOMES WITHOUT HANDS. 



creature holds itself to the extremity of the case by means of 

 hooks at the end of its body, which can grasp with some force, as 

 any one knows who has pulled a Caddis larva out of its house. 

 But when the case is fixed, the abdominal claspers of the larva 

 are attached to a pair of long foot-stalks, so that the creature can 

 extend its body to some distance from the entrance of the tube. 



We now turn to the warmer seas, and shall there find some 

 most magnificent examples of subaquatic homes. 



Our. first examples of these will be the wonderful creatures 

 wtich are classed together under the general term of Cobals, and 

 which are so familiar to us either in a manufactured state or as 

 ornaments for the drawing-room. How vast are their submarine 

 labors is evident from the enormous "Coral-reefs" which they 

 raise, and which form great islands whereon an army can live, 

 and inlets wherein a fleet can ride securely at anchor. 



Before proceeding farther in the history of the Coral and its 

 submarine home, we will see how it extends itself with such won- 

 derful rapidity, and what is the process that enables fresh colo- 

 nies to establish themselves, and existing colonies to spread them- 

 selves, both these operations being conducted on different princi- 

 ples. 



How the Coral grows is a problem which was unsolved until a 

 comparatively late period. Not only were naturalists ignorant of 

 its development, but they did not even know in what kingdom 

 to place it, whether vegetable or mineral. Opinions were long 

 divided on this point, the men of greatest reputation inclining to 

 the belief that it was mineral, while a very few thought that it 

 must be vegetable, and that the flower-like rays of the polype 

 were veritable submarine blossoms. But when a more careful 

 observer announced that the Coral was really the production of 

 an animal, both parties united in ridiculing his theory, and for a 

 while the animal origin of Coral was put aside by the scientific 

 world. Truth, however, prevailed, as it always will do, sooner or 

 later, and every one nowadays knows that Coral is the production 

 of animated beings. 



Still, although the general fact is known, its details are not so 

 familiar. 



In the active season of Coral life, that is, from May to August 

 or September, millions of young Corals are launched into the 

 world. When they first pass into the sea from the mouth of their 



