BEHAVIOR IN LOWER METAZOA 241 



they perform varied movements, till one of these "accidentally" re- 

 moves the source of stimulation. How this may develop into more 

 directly regulatory reactions we shall consider in the next section. 



The same qualities are shown in certain experiments of Preyer in 

 which he attempted to confine the starfish by means of large, flat-headed 

 pins. These were placed in the angles between the rays, close against 

 the disk, and driven into the board on which the starfish lay. They 

 thus held it down without injury. The starfish in the course of time 

 escapes from the pins, but only after much effort. The animals try 

 successively various methods, " now they seek to force themselves through, 

 now to climb over the top, now to push through by turning on one side." 

 In scarcely any two cases does the process of escape occur in the same 

 way, according to Preyer. The behavior is as far as possible from that 

 of invariable reflexes always occurring in the same way under the same 

 external conditions. 



One further point mentioned by Preyer is of great interest. He says 

 that when the experiment is repeated with the same individual, the 

 time required for escape becomes less. The number of useless move- 

 ments, "superfluous twistings, feelings about, and forward and back- 

 ward motions," becomes less the oftener the individual has been placed 

 in such a situation. If this is true, we have in so low an animal as the 

 starfish regulation through the selection of conditions produced by 

 varied movements passing into a more directly regulatory action; in 

 other words, what is commonly called in higher animals intelligence. 

 There seems to be no reason for doubting Preyer's observations on this 

 point, but on account of their great importance they should be repeated 

 and verified or refuted. 



Many other illustrations of behavior of the general character set 

 forth above could be presented from the valuable work of Preyer (1886). 

 It has become the fashion to neglect and even speak slightingly of the 

 work of Preyer on the behavior of the starfish. This seems to be due 

 to the tendency observable in recent scientific literature to represent all 

 such matters as extremely simple and reducible to separate well-known 

 mechanical factors, and to avoid all experiments tending to reveal the 

 fallacy of this view. Preyer was not afraid to open his eyes by properly 

 designed analytical experiments to the complexity and regulatory charac- 

 ter of the behavior. Such thorough and detailed studies of animal be- 

 havior as that of Preyer on the starfish are rare at the present time ; his 

 work stands in this respect in most refreshing contrast with some of the 

 superficial work recently put forth. The excellent work of Romanes 

 (1885) had already, before Preyer, brought out many examples of the 

 style of behavior we have illustrated above. 



