TRACKS IN THE SAND 79 



pend on their clicvaux-dc-frisc to protect thcni 

 from attack, but this does not always avail. 

 During the fall migrations at Ipswich I once 

 watched within a few feet a hermit thrush pick- 

 ing at a woolly-bear caterpillar on the ground. 

 I soon saw that the thrush's efforts were effec- 

 tively directed, for the hairs were fast disappear- 

 ing from the victim. At last a black, naked 

 worm, entirely devoid of the thick coat of hairs, 

 remained. The hermit thrush then picked his 

 victim up in his bill, swallowed it, flew to a low 

 branch, wagged his tail up and down in his 

 characteristic manner, chucked a few times with 

 satisfaction, and was off. 



On the steep side of a dune a caterpillar had 

 made repeated efforts to ascend, but losing its 

 foothold in the loose sand had rolled down. Yet, 

 like Bruce's spider, it tried, tried, tried again. 

 The picture in the sand suggested the outline 

 of a jagged mountain range or a temperature 

 chart. 



