USELESS HABITS IN TWO BRITISH NEWTS. 



169 



No. 16, which became partially disintegrated after a thirty 

 minutes' interval, but was very rapidly re-acquired. Three more 

 Great Cresteds were tested, the trials succeeding each other at the 

 same pace with periodic intervals. They all showed rapidity in 

 forming the simple r habit of movement, and equal rapidity in 

 losing it. Another was tested at intervals of fifteen minutes, and 

 at the end of twenty successive tests completely failed to form 

 any r habit. 



The Newt's capacities for forming simple movement habits 

 were also tested by putting them in salt solution contained in 

 narrow bottles with variously shaped necks. A glance at Fig. 4 

 shows that the trick to be learnt was a reversal of their position, 

 and then out at the top. The first bottle was learnt, on an 



Z> 



l 3 



Fig. 4. — Height of each bottle = 6 in. Diameter at the bottom = 

 3£ in. to 4 in. 



average, after three trials. The first trial always showed the 

 Newt persistently ''nosing" the bottom. The second and third 

 usually saw the time reduced to its smallest limits. The time 

 occupied in the initial "nosing" in No. 1 trial varied a great 

 deal, but rarely exceeded three minutes. It is all the more 

 surprising therefore to find that a certain male of M. cristata 

 nosed the bottom for forty minutes, after which more salt was 

 added, with the result that it shot out quickly. The second trial 

 occupied sixty-two seconds ; No. 3, three minutes forty-five 

 seconds ; No. 4, twenty-five seconds ; after which the time was 

 reduced, in two more trials, to the minimum. The fact that 

 this particular Newt was very thin and emaciated is suggestive. 

 The necked bottles made very little difference in the rapidity 

 with which the Newts learnt to reverse, the trick being acquired 

 in from five to six trials as a rule. 



