564 



SCIENCE 



[N. S. Vol. XXX. No. 773 



So intent was the snake upon mastering 

 the lizard, that it paid no attention to me, 

 standing there as quietly as a statue. Sev- 

 eral times the pursued lizard and the chasing 

 snake passed across my feet. At one time, 

 the lizard, on escaping from the snake, 

 darted up a tall tree. The snake followed. 

 Here the four articulated limbs of the former 

 gave it a decided advantage. After darting 

 up the tree for a short distance, the lizard 

 paused and glanced backward. As soon as 

 the snake had approached quite near, the liz- 

 ard darted ahead a short distance and then 

 again paused and glanced backward. These 

 reciprocal movements were repeated several 

 times. Then, all of a sudden, the snake 

 dropped to the ground. The lizard continued 

 to gaze downward. About a foot from the tree 

 upon which the lizard was resting, head down- 

 ward, there stood another tree. Spirally up 

 this trunk the snake quietly and slowly 

 climbed, until it was a few inches above the 

 level of the lizard. The unsuspecting lizard 

 was scrutinizingly gazing downward. Quietly 

 and quickly the snake extended the front por- 

 tion of its body, and, with a sudden dart of 

 the head, knocked the lizard to the ground. 

 Before the latter had time to recover from the 

 effect of the unexpected blow, the snake had 

 dropped to the ground and recaptured it. The 

 lizard was not yet conquered; but this article 

 is concerned only with the behavior up to this 

 point. 



This behavior puzzled me for a number of 

 years. I was reluctant to call it an exhibi- 

 tion of logical judgment; yet it seemed en- 

 tirely too complex to be regarded as reflex ac- 

 tion and too individualistic to be considered 

 instinctive, in the ordinary sense. From the 

 nature of the case, tropisms, as defined by 

 Loeb, are out of the question. Nor could it 

 be considered a " trial and error " response ; 

 for there is no series of errors followed by a 

 blundering into a solution and a gradual 

 " stamping in " of the appropriate response. 



The problem that confronted this snake 

 was how to overpower that lizard. Until the 

 lizard climbed the tree, the follow-the-stimu- 

 lus movements, which were either instincts or 



habits, were sufiicient to cause the capture of 

 the lizard: but, the moment the latter as- 

 cended the trunk of that tree, those move- 

 ments, unmodified, were inadequate. Sud- 

 denly the behavior of the snake changed. It 

 paused, then immediately met the situation 

 with a response which was a special modifica- 

 tion to suit a special circumstance; and this 

 is what we mean by a practical judgment. 



I am well aware that some will call this an 

 anecdote and desire to throw it out of court, 

 because it was not conducted in a laboratory, 

 under laboratory conditions, and because we 

 do not know the whole past history of the 

 snake and its ancestors. Nevertheless, I am 

 coming more and more to believe that ignor- 

 ing the spontaneous behavior of animals in 

 their natural environments hinders rather 

 than helps the solution of the problems of 

 animal behavior; for, it is in just these situa- 

 tions that the animals are apt to be resource- 

 ful. More caution is needed to interpret be- 

 havior in the open than under laboratory con- 

 trol; but the difficulties of the task furnish no 

 excuse for avoiding it. I am a stanch advo- 

 cate of laboratory work ; but, at the same time, 

 I feel that data derived from accurate field 

 work are of greater value than many seem to 

 think. Accurate observations made, by 

 trained observers, in the field furnish us with 

 stubborn facts that should not be ignored ; they 

 need to be interpreted in an unprejudiced 

 manner. Laboratory work and field work 

 should go hand in hand. C. H. Turner 



Summer High Schooi., 

 St. Louis, Mo., 

 April 29, 1909 



QUOTATIONS 



INCORPORATED BENEFACTORS 



Benefactors die; universities abide. At 

 least, that has been the case in the past. But 

 in this age of organization, benefactors have 

 learned to perpetuate themselves as corpora- 

 tions. And we now have institutions chart- 

 ered by acts of congress to disburse for educa- 

 tional purposes the charities of millionaires. 

 The rich philanthropist, who objectifies him- 

 self in such a benevolent corporation, of 



