AN INVISIBLE RAILWAY. 129 



has of bringing home to its mouth the various matters laid hold 

 of by its outstretched tentacles. These organs are endowed with 

 an adhesive property which enables them by mere contact to 

 hold fast minute particles of matter. They may often be seen 

 stretched out to their full length, pulling and straining at some 

 minute object, which they are endeavouring to dislodge ; pre- 

 sently the object gives way, and is seen adhering to the tentacle. 

 But now, strange to say, the object which has thus been torn off is 

 seen quickly travelling along the surface of the still outstretched 

 tentacle towards the mouth of the worm, which is protruded 

 from the tube, and may be seen distinctly to open to receive the 

 expected morsel. It is just as though the surface of the tentacle 

 was furnished with an invisible railroad, trucks and locomotive 

 all complete. But it is not merely for the conveyance of pro- 

 vender that this curious system of traction is of service ; it is 

 equally available for the conveyance of the materials with which 

 the tube is gradually built up, and the attentive observer will 

 often see the little worm bringing home the minute particles of 

 sand and dirt which lie within the sweep of its tentacles, and 

 then, withdrawing within its tube, employing the tips of its 

 tentacles in adjusting the materials in their proper position. 



The little Spio is minute and altogether unattractive in ap- 

 pearance, but it is extremely hardy, and need never be wanting 

 amongst the inmates of the Aquarium. In every respect a con- 

 trast to this, is the gorgeous Annelid already alluded to, the Sea- 

 mouse (Aphrodita aculeatci), which is the largest of our native 

 worms, being between three and four inches in length, and half 

 as wide as it is long. It is of a flattened oval form, and is 

 covered along the sides on the upper surface with a dense 

 coating of bristles, which are adorned with brilliant iridescent 

 colours, that rival the glowing tints of the Humming-bird. But 

 unfortunately for the Aquarium-keeper the Sea-mouse speedily 

 languishes and dies in confinement, and not only so, it has no 

 idea at all of making the most of itself. Its proper home is in 

 the deep water, and it is no sooner dredged up from its muddy 

 haunts, and honoured with a place in the Aquarium, than it 

 Blinks away into some obscure corner, and there remains apathetic 

 and motionless, without giving one a single glance at its beau- 

 tiful robe of many colours. It is very common on some parts 

 of the coast, and after high winds may constantly he found cast 



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