208 THE MICROSCOPE. 



which after a time fall like blighted blossoms off a tree; they do be- 

 come ' old in their youth/ and, rendered hebetous and unfit for duty or 

 ornament by age or accident, the common trunk throws them off, and 

 supplies its wants by ever-young and vigorous growths. The pheno- 

 mena are of those which justly challenge admiration, and excuse a sober 

 scepticism, so alien are they to all we are accustomed to observe in 

 more familiar organisms. Faithful observation renders the fact unde- 

 niable ; but besides that, a reflection on the history of the Hydra might 

 almost have led us to anticipate such events in the life of these 

 Zoophytes. ' Verily, for mine own part, the more I look into Nature's 

 works, the sooner am I induced to believe of her even those things that 

 seem incredible' " Baker. 



TUBULARID^E. 



The third family are the Tubular or Vaginated Polyps : of an arbo- 

 rescent appearance, the animals live near the end of the branches, and 

 are found attached to stones, sea-weeds, and shells. The Tubularia 

 indivisa, or individed tubes, rise up like a tuft of herbage, of a horn 

 colour, to the height of twelve inches. Ellis says, " they seem part of 

 an oat-straw with the joints cut off." At the summit protrudes the 

 scarlet-coloured polyp, well furnished with tentacula, and connected 

 with a pinkish fluid that fills the tubes. It was in this that Dr. Eoget 

 discovered the singular peculiarity of a circulation, similar to that in 

 many plants, carried on without the mechanism necessary in higher 

 organised animals : he says, " In a specimen of the Tubulama indivisa, 

 when magnified one hundred times, a current of particles was seen 

 within the tubular stem of the polyp, strikingly resembling, in the 

 steadiness and continuity of its stream, the vegetable circulation in the 

 chara. Its general course was parallel to the slightly spiral lines of 

 irregular spots on the surface of the tube, ascending on the one side, 

 and descending on the other ; each of the opposite currents occupying 

 one-half of the circumference of the cylindric cavity. At the knots, or 

 contracted parts of the tube, slight eddies were noticed in the currents; 

 and at each end of the tube the particles were seen to turn round, and 

 pass over to the other side. 



The particles carried by it present an analogy to those of the 

 blood in the higher animals on one side, and of the sap of vegetables 

 on the other: Some of them appear to be derived from the digested 

 food, and others from the melting down of parts absorbed ; but it would 

 be highly interesting to ascertain distinctly how they are produced, and 

 what is the ofliee they perform, as well as the true character of their 



