NATURAL HISTORY WORK IN CART AGO 73 



the richest place we found near Cartago and became our 

 favorite collecting ground here. 



One lane led directly to the town refuse heap — where we 

 went once and having watched and listened to the horde of 

 vultures had no desire to go again. However in justice 

 both to the town and the vultures it should be said that this 

 garbage heap was astonishingly inoffensive, and moreover 

 flies were not a great pest in Cartago. The day we went 

 along this lane was May 10, 1909. The rains of the two 

 preceding days had changed the dusty roads to damp and 

 produced little swampy spots in the pastures. Over one of 

 these swamps a species of dragonfly (Sympetrum illotum 

 virgulum) was swarming. The males have bright red bodies, 

 the females dull brown and many pairs were engaged in lay- 

 ing eggs. Big blue and blackish Aeshna dragonflies flew 

 swiftly about and several smaller species were found here 

 and there by the roadsides. 



There was an exceedingly handsome frog here {Agalych- 

 nis helence), one of which we took to the hotel and kept for 

 some days. When "asleep" its body, exclusive of legs, was 

 two and one-half inches long. Ordinarily the upper surface 

 of body and legs was a bright pea-green; below, the body was 

 speckled white and reddish-brown, with a band of brilliant 

 beautiful blue on each side of the abdomen. There were 

 great color changes, however. When first caught it was 

 pale green; when we took it out of the vasculum at home it 

 was a dark dirty green with pale spots on the back. While 

 we photographed the frog it grew light again with paler spots 

 over the back. After nightfall it was again very dark, but 

 although it spent the night in a dark cupboard it was pale 

 green when we first looked at it in the morning and again at 

 4.30 P. M. The tips of all the toes (four on the front, five 

 on the hind feet) are expanded into large fleshy discs with 

 which the frog climbs readily. It was able to cling to the 



