Professor Jones, who affirms that in the latter suggestion Sir J. Dalyell has nearly hit upon the true solution of the problem, thus gives what he considers to be the correct mode of procedure on the part of the Star-fish: 'Grasping its shell-clad prey between its rays, and firmly fixing it by means of its prehensile suckers, it proceeds deliberately to turn its stomach inside out, embracing in its ample folds the helpless bivalve, and perhaps at the same time instilling some torpifying fluid, for the shells of the poor victim seized soon open, and it then becomes an easy prey.'
Now, many fishermen with whom I have conversed hold the same opinion as Bishop Spratt, and believe that when the oyster is gaping the Star-fish insinuates a finger, and hastily scrapes out the delicious mouthful; nay, further maintain that the Star-fish is far from being successful at all times, very often, especially when there has only been one ray inserted, the frightened oyster grasps it with all his might, and obliges his discomfited opponent to retire minus a limb.
If the writer might venture to suggest an opinion, he would express his belief that the following is the correct account of the state of matters. He believes with the fishermen that frequently the star-fish begins his attack by inserting an arm, but he does not believe that the oyster under such circumstances escapes with life. Let us suppose the star-fish to have succeeded in insidiously introducing a ray within the shell of the apathetic oyster, and that the oyster immediately resented such intrusion by closing his shell with all the force he can exert. The opposite argument at this stage is, that the intruder is obliged from pain to abandon his hold, and even pay for his audacity by the forfeit of a limb. But against this we advance the notorious fact, that the star-fish, like so many marine creatures of a similar organization, is remarkably indifferent to pain. I therefore believe the true explanation to be, that the oyster being unable to sustain such continued muscular exertion for nearly so long a time as the star-fish can tolerate the pressure upon its ray, the latter is consequently, in the long run, successful.
The number of rays in the several genera of the true Star-fishes is extremely various. In the genus Uraster, as we have seen, five is the predominant number. If we turn to the two species which comprise the genus Cribella, we still find the quintuple arrangement adhered to. In Solaster endeca, on the contrary, the rays vary from nine to eleven, and even reach as high as twelve or fifteen in Solaster papposa.
In the genus Palmipes we have the pentagonal form, it is true, but the space between each ray is filled up, so as to resemble the webbed foot of a bird, hence the popular title of this solitary species, 'The Bird's-foot Sea-star.' 'It is the flattest of all its class, and when alive it is flexible like a piece of leather.' Passing by the 'Cushion-stars' (which have five angles—it seems a misnomer to call them rays), which connect the true Star-fishes with the Sea-Urchins, we come lastly to the 'Lingthorn,' Luidia fragillisima, with its seven rays. This is the animal of which Professor Forbes discourses so pleasantly about its winking derisively at his despairing endeavours to preserve even a small portion of what at that time was his maiden specimen. The Luidia is even more brittle—more regardless of its wholeness, than the Ophiuræ, which renders the capture of a perfect specimen a most difficult task.