ASTERIAS. 99 



I speak with diffidence ; but possibly the progress is beheld as re- 

 presented, Plate XVII. fig. 2 ; Plate XIX. figs. 2, 3, 4, 5, 6,— the first 

 representing the molecules or ova, and the last the young of perfect 

 form. 



All these, it will be observed, appear to be advancing to perfection. 

 But, not having seen their origin, I am ready to give them as a general 

 illustration of the progTessive improvement, without insisting that they 

 were necessarily the young of the Asterias rubens. 



They occurred at different tunes, though the intervals were not 

 great compared with the irregularities constantly embarrassing the his- 

 toiy of such marine productions. 



The ova are seen Plate XVII. fig. 2. The animal, Plate XIX. fig. 2, 

 evidently had recently quitted the ovum. It was little above half a line 

 in diameter, irregularly tending to a circular form ; of variable shape, of 

 soft homogeneous aspect : endowed with slow progression and slight ad- 

 hesion. Some short suckers projected from the cu'cumference, but no 

 indication of rays. This subject occurred on April 29, and was delinea- 

 ted on May 2, enlarged. The form of another specimen, under a line in 

 diameter, delineated May 16, was much improved, for the incipient form 

 could be distinctly determined ; fig. 3, upper surface ; fig. 4, under sur- 

 face, both enlarged. Above a dozen were found among miscellaneous 

 collections, on May 26, which, still in an early stage, had attained higher 

 perfection. They are represented as of the natural size, fig. 5 ; one en- 

 larged, fig. 6. 



The roe had been previously discharged from several of the Asterias 

 rubens and several of the Asterias glacialis, all dissected on the 11th of 

 July. 



Many marine products are totally lost in earlier age, if separating 

 from the parent, and multitudes destroyed by sudden decay ; thence it 

 can be principally from accident, if any are preserved on quitting the 

 ovum. 



This species, the rubens, lilce the preceding, is extremely subject to 

 mutilation of the rays. Of the complement many have four, three, two, 

 and some only one. But, the reproductive energies being powerful, 



