ON THE COMMON BRITTLE STAR, 43 
and after such examination, let Fig. 1 (of the minute form 
before alluded to) be compared with it, and it will be seen that 
there is not the least resemblance between them further than that 
each is a Star-fish possessed of five-rays; that in the large form 
the spines are long and pointed; in the small, fan-shaped, flat, and 
spreading: how, then, can these flat forms ever merge into the 
long and pointed? Such thoughts as these suggested themselves 
to my mind as I endeavoured to account for the difference when 
first the subject was taken up, feeling almost certain that my 
specimen had something to do with the common Brittle Star; 
other specimens, and more time spent in their consideration, 
solved the problem, and it will now be requisite to confine our- 
selves to a careful consideration of some of the changes that a 
form similar to Fig. 1 goes through, before appearing as a per- 
fect and fully developed individual, similar to the Brittle Star, 
supposed to have been obtained from the fishing lines. 
Premising, therefore, that the earliest form of a Star-fish is 
“ an oval, ciliated body, like an infusory animalcule, without 
organs or distinction of parts,”* and that it passes through 
various changes before partaking of the radiate form and charac- 
ter of the class, for full particulars of which I must refer my 
readers to the admirable researches of Miiller and Sars in the 
“ Annals.” 
It will be sufficient for my purpose if we take up the subject 
where these Naturalists appear to have left it, and assume that 
the animal under consideration is, in its young state (or that 
immediately preceding its assumption of the distinctive features 
of its class) a little radiate star, the arms or rays being repre- 
sented by short warts or lobes standing out from the disc. 
The first segment is produced from the lobes, before alluded to, 
and these assume the form and character of segments by the 
* See T. H. Huxley, Annals, and Mag. Nat. History, July, 1851. 
+ The smallest and most immature form of Ophiocoma rosula that I have obtained 
shows four flat fanshaped spines on the first ray joint, or thatnearest the disc: two claws or 
hooks, and two small narrow spines (just forming) on the second joint; and beyond these, 
the tip hooks and small lobes in a very early stage. From this it will be seen, that the first 
segment or joint produces flat fan-shaped spines in the first instance, whereas the second 
joint deviates from this, and first forms claws. 
