418 HOMES WITHOUT HANDS. 



If possible, the observer should preserve specimens of the 

 hooks for the microscope. He will not want for examples, as 

 the creatures have a habit of coming out of their tubes and dy- 

 ing on the floor of the aquarium, to the great discomfiture of the 

 owner. I find that Deane's gelatine answers very well for the 

 purpose, and the specimens which have just been mentioned are 

 now in perfect preservation, after having been in the gelatine for 

 some six years. 



It is very curious to watch the different methods by which the 

 Serpula protrudes and withdraws itself. When it retires into the 

 tube, it vanishes so quickly that the eye can not follow its move- 

 ments, but when it protrudes itself, it does so in a very deliberate 

 manner, seeming to feel its way cautiously toward the light, and 

 to be ready to dart back again with or without reason. 



The organs by means of which it protrudes itself are placed 

 close to those which withdraw it. Through the foot-warts pro- 

 ject a number of stiff, transparent bristles, which are wonderfully 

 like the many-barbed spears of savage nations. I have an arrow 

 of the Tonga Islands which is almost an exact reproduction of a 

 foot-bristle of the Serpula, saving that wood and bone are substi- 

 tuted for the purer material of the bristle. The shaft runs quite 

 straight, but toward the tip the bristle is flattened and widened 

 into a head just like that of a spear. The head has a very slight 

 curve, is sharply pointed, and is armed with a double row of barbs 

 on the edge. A great number of these bristles are clustered to- 

 gether, so that their united force is really considerable. 



Supposing that the animal is fully expanded, and that the ob- 

 server has succeeded in placing his eye to the glass without 

 alarming the sensitive creature, he will see a wonderful sight. 

 In its way there is nothing which surpasses in beauty the ex- 

 panded gill- tuft of a Serpula in perfect health. The long feathery 

 gills radiate from the tube in a curve which combines grace and 

 force in no ordinary degree, while the beautiful colors that glow 

 as the blood courses through their translucent substances are far 

 beyond the power of description. 



One use of the gills is evident enough. They serve for respi- 

 ration. But they also answer another purpose, and aid the ani- 

 mal in procuring food. Being necessarily stationary, it can not 

 roam about in search of food, and its appetite is so great that it 

 would soon die were it to depend for subsistence on the nourish- 

 ment which might be brought within its reach by the waves. 



