114 



LIFE, IN ITS LOWER FORMS. 



four long slender calcareous rods, arranged two in front 

 and two behind, with connecting pieces going across in 

 a peculiar manner, and meeting at the top in a slender 

 head. 



On this shelly, fragile, and most delicate framework, as 

 on a skeleton, are placed the soft parts of the animal, a 

 clear gelatinous flesh, forming a sort of semi-oval tunic 

 around it, from the summit to the middle, but thence 

 downwards the rods individually are merely encased in 

 the flesh without mutual connexion. The interior of the 

 body displays a large cavity, into which a sort of mouth 

 ever and anon admits a gulp of water. Delicate cilia 

 cover the whole integument, and are particularly large 

 and strong on the flesh of the projecting rods. 



The appearance of this most singular animal is very 

 beautiful ; its colour pellucid- white, except the summit of 

 the apical knob, and the extremities of the greater rods, 

 which are of a lovely rose-colour. It swims in an upright 

 position, with a calm and deliberate progression. The 

 specimens which we have seen were not more than one- 

 fortieth of an inch in length. 



From this form the Brittle-star is developed, but in a 

 manner unparalleled in any other class of animals. The 

 exterior figure is not gradually changed, but the star is 

 constructed within a particular part of the body of the 

 larva, " like a picHire upon its canvas, or a piece of em- 

 broidery in its frame, and then takes up into itself the 

 digestive organs of the larva." The plane of the future 

 Star-fish is not even the plane of the larva, but one quite 

 independent of, and oblique to it. Strange to tell, the 

 young Star does not absorb into itself the body of the 



