THE ENTOMOLOGIST. 59 



of the smaller ants already afTected by the poison, and they 

 themselves begin to bite, and in a short time become tlie 

 centre of fresh balls of rabid ants. The sublimate can only 

 be used effectively in dry weather. At Colon I found the 

 Americans using coal-tar, which they spread across their 

 paths when any of them led to their gardens. I was also told 

 that the Indians prevent them from ascending young trees by 

 tying thick wisps of grass, witli the sharp points downwards, 

 round the stem : the ants cannot pass through the wisp, and 

 do not find out how to surmount it, getting confused amongst 

 the numberless blades, all leading downwards. I mention 

 these different plans of meeting and frustrating the attacks of 

 the ants at some length, as they are one of the greatest 

 scourges of tropical America, and it has been too readily 

 supposed that their attacks cannot be warded off, T myself 

 was enabled, by using some of the means mentioned above, 

 to cultivate successfidly trees and vegetables of which the 

 ants were extremely fond." — P. 78. 



Spiders. — " Near the river were some fallen-down wooden 

 sheds, partly overgrown with a red-flowered vine: here a 

 large spider {Ne phil a) hnWi strong yellow silken webs, joined 

 one on to the other, so as to make a complete curtain of web, 

 in which were entangled many large butterflies, generally 

 forest species, caught when flying across the clearing. I was 

 at first surprised to find that the kinds that frequent open 

 places were not caught, although they abounded on low, 

 white-flowered shrubs close to the webs; but, on getting 

 behind them and trying to frighten them within the silken 

 curtain, their instinct taught them to avoid it, for, although 

 startled, they threaded their way through open spaces and 

 between the webs with the greatest ease. It was one instance 

 of many I have noticed of the strong instinct implanted in 

 insects to avoid their natural enemies." — P. 108. 



Spiders. — * * * * "To return to the spiders. Besides 

 the large owner and manufacturer of each web, who was 

 stationed near its centre, there were on the outskirts several 

 very small ones, belonging, 1 think, to two different species, 

 one of which was probably the male of a Thomisus, the males 

 in this genus being much smaller than the females. 1 some- 

 times threw a fly into one of tlie webs : the large spider would 

 seize it and commence sucking its blood; the small ones, 



