98 THE SWAN AND HER CREW. 



genera Nais and Syllis, marine worms of no special interest to 

 the ordinary observer, but those who have watched their habits 

 closely, tell us of the almost extraordinary power of spontaneous 

 division which they enjoy. Self-division, as a means of propa- 

 gation, is common enough among the lower members of both 

 animal and vegetable kingdoms, but the particular kind to 

 which I refer now, is, I believe, peculiar to these singular worms. 

 At certain periods the posterior portion of the body begins to 

 alter its shape materially, it swells and grows larger, and the 

 transverse segments become more strongly marked. At the 

 last joint, at the point where it joins the first segment of the 

 body, a true head is formed, furnished with antennae, jaws, 

 and whatever else goes to make a marine worm " perfect 

 after its kind," and forthwith the whole drops off. a complete 

 animal, capable of maintaining a separate existence. Whether 

 the process goes on for ever that is to say, throughout all 

 generations of course, no one can tell; but if it does and 

 there is no reason to suppose the contrary then it is self- 

 evident that the posterior portion of one of these worms is, as 

 I observed before, practically never dying. It is simply fitted 

 every now and then with a new head ! In fact, the. tail of the 

 first Syllis ever formed, provided it has had the good luck to 

 escape external accident must still be in existence a truly 

 venerable animal, and without controversy the 'oldest in- 

 habitant ' of the seas." 



" It strikes me," said Frank, " that that animal would be 

 something like the Irishman's stocking, which he had worn for 

 a score of years. It had been re-footed and re-legged several 

 times, yet he always asserted that it was the original stocking, 

 although there was not a particle of the old stuff in it." 



" What a wonderful tip to his tail some animal has got then, 

 if that is true," said Jimmy. 



I cannot say whether the statement of the writer in Science 

 Gossip is strictly accurate, for who can decide when doctors 

 disagree ; but it seems plain enough that the process of 

 generation by sub-division is far nearer the longed-for perpetual 

 life, than anybody has been able to get to the coveted solution 

 of the problem of perpetual motion. 



" Do you know that the water we are sailing on is higher 

 than the marshes around us ? " said Frank. 



" Yes, and all those windmills are to pump the water up from 



