But undoubtedly new for these animals was the position in which they were fastened to a board by five long pins with broad heads, which Preyer drove in close to the central disc between the rays, so that the star-fish, as it seemed, was fastened to its resting-place in a way that admitted of no escape. Nevertheless, the star-fish found a means of freeing itself with ease and elegance from this constrained imprisonment in a great variety of ways, even when the exterior parts of their bodies were girded in by a much greater number of pins. Ordinarily they began by shoving one of their rays, accompanied by a backward bending movement of its two companions, far out between the two encompassing pins, and then drew with the greatest care first the one and then the other adjacent ray through the same narrow avenue of escape, whereupon then the two remaining rays, the one slightly overlapping the other, were enabled to follow with perfect ease. (See Fig. 6.) A practised knot-untier who had studied the position could not have given them better advice. But if no agreement of plan and purpose existed in this case between the separate rays, if each ray sought to free itself of its own accord, a successful extrication from the difficulty could hardly have been foreseen; and we must infer from this great unanimity of action in times of danger. [Illustration: Fig. 6.—EXTRICATION OF STAR-FISH IMPRISONED INTERRADIALLY BY TACKS. (After Preyer.) _1._ Original encompassment. _2._ First stage of extrication. _3._ Second stage. _4._ Third and last stage. The smaller figures indicate the successive positions of the same rays.] Preyer thinks that at times the concurrence of all the rays in matters of concerted action might have to be effected by first obtaining the concurrence and assent of any individual ray that might be hostilely disposed; he holds it as not improbable that profound dissensions may arise between the united brothers, and refers to the fact that perhaps the voluntary section of a star-fish into a three-rayed and a two-rayed portion,—which frequently takes place,—may have to be regarded as the violent dissolution of a community of fellow animals formerly living in harmony, but now lapsed into a state of conflict. We shall pass this view by, however, to point out in a few words Preyer's general inferences with regard to the mutual relation of the five communal souls. Progression and flight in a direction once taken and unimpeded by obstacles,—an observation often made and easily verified,—the acrobatic performances, and lastly the intelligent behavior, so to say, of imprisoned and fettered star-fishes, prove that generally, and especially in moments of peril, strength-giving unanimity prevails.