192 IN THE WILDS OF SOUTH AMERICA 



existence is hardly suspected by the casual observer. What 

 at first appeared to be a maze of cobwebs filling the en- 

 trance to a dark cavern under the roots, resolved into a 

 moving, living mass. A closer inspection, and small, black 

 specks could be distinguished in the madly weaving and re- 

 volving haze, and also long, threadlike legs dangling so idly 

 that one wonders why they do not become hopelessly en- 

 tangled with those of then- neighbors. This peculiar, waver- 

 ing flight of the crane-fly seems to form the delicate, 

 spidery creature's chief occupation, for I rarely found them 

 at rest. Presently, other little insects, encouraged by the 

 silence, make their appearance. First among them may be 

 a small Gastaracantha spider, slowly letting itself down from 

 an overhead twig on a thread of finest gossamer. At first 

 glance one may easily mistake the insect for a minute crab 

 that has fallen from the leafage into a silken snare, but when, 

 at the watcher's first movement, it either runs nimbly up 

 the dangling thread, or drops to the ground with a rapid 

 slacking of line, one is convinced that it must be a spider. 

 The hard shell, or back, is fringed with sharp, upturned 

 spines and is of an orange color marked with a number of 

 small black dots. 



After a shower, mosquitoes were numerous and attacked 

 with the utmost persistency. This irresistible thirst for 

 blood is very extraordinary; it does not seem possible that 

 more than a very small proportion of the countless millions 

 of these insects living in a given area ever have an oppor- 

 tunity for satiating their appetite for blood during their 

 entire lifetime; yet the instinct remains, and they attack 

 on sight ferociously and without hesitation any living thing 

 whose skin their beaks can penetrate. It is also a well- 

 known fact that malarial fever, so prevalent in the tropical 

 lowlands, is transmitted by a genus of mosquito, Anophiles. 

 The germ of this fever, however, passes only one period 

 of its existence within the insect's body, and the spores 

 must be secured from some living creature, and after de- 

 velopment transmitted to another to complete the life cycle. 



