MINUTE AQUATIC ANIMALS. 69 



ing the arms, speedily provides itself with a new body and tail, and the lower 

 part pushes forth a fresh body and head with its slender arms. If the animal is 

 slit down from the head to the tail, but is not quite severed, each of the two 

 parts, thus left hanging together, becomes a perfect polype, and they live and 

 roam through the water indissolubly linked to one another. Nay, more, if a 

 polype is turned inside out, it soon accommodates itself to this new arrangement ; 

 for the original outer skin, now lining the interior cavity, performs the office of 

 digestion ; while the coating of the former stomach becomes the covering or 

 skin of the polype. 



The possession of this strange faculty by the polype is not a matter of 

 inference or conjecture ; inasmuch as it has been proved by experiments, beyond 

 the possibility of a doubt. It was first discovered about a century ago, by Mr. 

 Trembly, of Holland, whose statements were afterwards verified in England in 

 every important particular, by the experiments of Mr. Henry Baker, of the 

 Royal Society ; and still later by Pritchard, who thus details one of his experi- 

 ments. " Having selected a brown polype out of a glass vase containing a good 

 supply of them, none of which had more than seven arms, I severed it obliquely, 

 the upper part comprising the greater portion of the head and four arms ; the 

 lower part being the tail with the remainder of the head and two arms. These 

 pieces were then put in a four-ounce phial of water, with a few small Crustacea, 

 where they sunk to the bottom, apparently lifeless. Three hours after the 

 operation I examined them, and found them in the same state. 



Twelve hours after this I found the lower part attached to the side of the phial 

 by its tail, with its arms extended in quest of food ; the upper one still remaining 

 at the bottom, but with its arms extended like the other. 



On the second day, a new tail was completed to the upper part of the polype, 

 and the rudiments of additional arms were developed in both, and each portion 

 appeared in good health. On the third day, the new arms were nearly of the 

 same size as the others, and in less than a week each of the two polypes had a 

 young one sprouting from it. The most curious circumstance connected with 

 this experiment was, that the two new polypes had each ten arms, while that 

 from which they were produced, as well as those which were in the same vessel, 

 had only six or seven. 1 ' 



The number of parts into which this creature is divided presents no obstacle 

 to the operation of this extraordinary law o% vitality ; for a single polype has 

 been cut into ten pieces, and each part soon became a complete animal. 



THE ROUND LYNCEUS, OR MONOCULUS. This name is given to the curious 

 little creature, which is shown highly magnified in figure 101. It is covered 

 with a delicate shell, presenting by its fine reticulations the appearance of mo- 

 saic work. This envelope, with its minute divisions, is beheld in the drawing at 

 a, and encases nearly the entire body of the animal. In some species the shell 

 is adorned with diamond-shaped figures, in others its surface is composed oi, 

 hexagons like that of a honey -comb ; and a diversity of other angular figures 



