COPEIA 105 



THE JUMPING ABILITY OF PLETHO- 

 DON AND ITS POSSIBLE BEARING 

 UPON THE ORIGIN OF SALTA- 

 TION IN THE ANCESTORS 

 OF THE ANURA. 



On the evening of August 18, 1917, at Snow- 

 ville, N. H., I picked up a gray-backed Plethodon 

 cinereus 71 mm. in total length. It was caught cross- 

 ing a sandy road just before dusk. While I held it 

 on one open hand, it surprised me by jumping to 

 the sleeve of my other arm. I experimented further 

 by holding my open right hand at varying distances 

 from the salamander on the left hand. In its efforts 

 to escape, the creature always scurried straight ahead, 

 in the direction in which it had been pointed, and 

 when it reached the edge of my palm, it leaped across 

 the open space to the other hand, repeatedly clearing 

 a distance of fully twice its length. In this manner I 

 kept it jumping rapidly for perhaps two dozen times 

 before it became sufficiently fatigued to quiet down. 



The fact that this salamander is a leaper may 

 possibly be known, but I had never before observed 

 it. I had always considered the terrestrial urodeles 

 as exclusively creeping animals, probably because I 

 had hitherto found them chiefly in the daytime, dur- 

 ing their inactive hours. This Plethodon was just 

 starting out on its nocturnal wanderings, and was 

 no doubt at its liveliest. I now understand how mem- 

 bers of the species cross deep ruts in roads, and how 

 they surmount such obstacles as logs and fallen 

 boughs in the boggy woods that they inhabit. The 

 discovery also throws light on the way that they cap- 

 ture Bibionid flies, winged ants, Collembola, and 

 other active insects, remains of which I have found 

 in the stomachs of Plethodon cinereus, taken under 

 dead logs in the early morning. I had often won- 

 dered how a sluggish salamander — a lowly creature 

 which I had supposed to move like a stranded mud- 

 puppy — could feed upon flying or jumping insects. 



