306 University of California PuMications in Zoology [Vol. 21 



tinned to dig until 4:09 and then it moved slowly along the west 

 side of the box. It continued to move around trying the earth and 

 the glass cover until, at 4 :13, it again started to dig in the southwest 

 corner. Digging lasted two minutes. After more traveling around 

 the box it dug two more minutes in the shadow. Meanwhile the sun 

 had moved so that only a small patch of sunshine was left in the 

 southeast corner. At 4 :23 the snake moved slowly down into the 

 southwest corner ; when two minutes later the blue filter was lifted 

 the snake was found two-thirds coiled in the depression it had made. 



On April 21, under blue light, the snake made several attempts 

 to cover its head, then dug once to the right in the northwest corner. 

 Twelve minutes later, at the middle of the side of the box, the snake 

 dug to the right and to the left. It tried twice to cover its head in 

 the sand, then dug again to the right and moved oif. Six minutes 

 later in the southwest corner it dug to the left, moved a trifle, and 

 dug to the right. A minute later it dug in the northwest corner once 

 to the left and tried to bury its head. 



This was the last time the snake was seen to dig. This circum- 

 stance may have been due to the fact that the extreme stimulation 

 of blue light was not used again. The first attempt, however, on 

 April 13, was made under electric light. More likely the loss of the 

 habit was due to the growing weakness of the snake, for the digging 

 required more effort than merely creeping into the sand. If a larger 

 rock had been put in the box soon after the snake was captured and 

 the sand left entirely undisturbed the snake might have made a 

 hollow under the rock. 



In loose sand the snake could bend its body freely and back up 

 rapidly. On April 11 when an attempt was being made to measure 

 the length accurately the snake was persuaded to creep into a glass 

 tube which was slightly greater in diameter than the animal's body. 

 The tube was put over the head and the snake poked until it moved in 

 to over two-thirds of its length. Then it suddenly began to back. The 

 tube w^as turned vertically with the snake's head downward; still 

 the snake backed out. When two-thirds of the body was out a finger 

 of the observer was placed under the tail. With that leverage the 

 snake finished the backing out process rapidly. When the animal 

 was on a smooth table it moved only with difficulty. 



The snake coiled rarely. Only once was it observed in that posi- 

 tion and then it was in a loose coil. Usually it was not even looped 

 unless it was in a small can in which it did not have room for stretch- 

 ing out more or less at full length. 



