80 A NATURALIST IN BORNEO 



it fly out of a tree I paid little serious attention to 

 his statement. However, some weeks later the same 

 man brought in a specimen of Chrysopdea chrysochlora 

 and said that he had seen this also fly out of a tree. 

 On cross-examination I found that by "flying" he 

 meant to say that the snake shot out at an angle from 

 a tree and descended in an oblique line to the ground 

 with its body held quite straight. The matter seemed 

 now to be worthy of serious investigation, and I gave 

 instructions that the next specimen captured was to 

 be brought to me alive, and eventually a living 

 example of C, ornata was found. As soon as I 

 handled the snake I gained some idea of the means 

 whereby it could "fly." The scales along the belly 



in snakes are broad plate-like structures, and in C. 

 ornata and also in C. chrysochlora each scale has a 

 hinge-line on either side, marked a in the adjoining 

 diagram. As the snake writhed about in my hands 

 I could feel that every now and then the ventral scales 

 by a forcible muscular contraction were drawn in- 

 wards, so that the snake became deeply concave along 

 all its under-surface. The scales moved inward on 

 their hinge-lines, and at the same time there was a 

 slight spreading out of the ribs. When the muscles 

 working the scales relaxed, the snake re-assumed its 

 ordinary cylindrical shape. The snake, in fact, may 

 be compared, when at rest, to a cylindrical piece of 

 bamboo ; when restive, to a cylinder of bamboo bisected 



