USELESS HABITS IN TWO BRITISH NEWTS. 219 



sequently), and only three went right over at the first time. 

 Several days later I found that three of the Newts refused to 

 leave the board, when it was placed on the floor of the room, so 

 that the height was only the thickness of the board, i. e. 2 ctim. 

 2 mm. One of the three perceived the edge when a couple of 

 centimetres away, and would draw back. However, when placed 

 immediately after on a piece of cork matting only 8 mm. thick, 

 they all three went over, but only after a pause of ten seconds in 

 two of the cases and eight in the other ! The rest refused a 

 height of 15 ctim. by eight to two. 



By experimenting with these Newts, when in this condition 

 of refusing low heights, I thought to be able to discover whether 

 they had any elementary power of judgment of height. The 

 results showed that they can recognize extremely low heights 

 (as might have been expected) up to between 5 and 8 ctim. 



The Newts, in all the experiments, were tested singly and in 

 series. Below are some of the best instances in which a Newt 

 showed its disinclination to go over 180 ctim. 



Singly : 1. 60 ctim. refused after pause of 75 seconds. 

 2- » ,, „ 3Q 



3. 20 ctim. „ „ 30 



4. ,, went over ,, 18 



5. ,, ,, ,, 20 



6. ,, „ ,, 10 



7. 60 ctim. „ „ 10 



8. 180 ctim. refused repeatedly, walking on the 



board for five minutes. 



9. 60 ctim. went over after a pause of 50 seconds. 



This shows how easily previous behaviour influences the 

 Newt, not, however, completely in the 180 ctim., although the 

 pause at the next drop of 60 ctim. was increased. Another 

 animal gave : — 



1. 60 ctim., over after 30 seconds. 

 2- „ „ 20 „ 



3. 90 ctim., over immediately. 



4. 180 ,, refused repeatedly. 



5. 60 ,, over after 60 seconds. 



s2 



