THE LIVING WORLD. 
25 7 
African travellers tell of the courage of the tsetse-fly which disputes with 
man the possession of the land; it has been known even to prevent either agriculture 
or exploration. In form not unlike our horse-fly. it resembles the snake in the 
secretion of the most deadly poison. To be sure this poison is fatal only to 
domesticated animals (except the goat and ass), but no industries can be carried 
on without the aid of our beasts of burden. The tsetse never goes in swarms, 
being fortunately few in number, and therefore its effect upon domestic animals 
is the more surprising. The buffalo gnats of Arkansas and other southern 
districts will occasionally worry cattle to death, but these attack in such great 
swarms as to fairly drain their victims of blood. The tsetse , on the other hand, 
while a blood-sucker, does not do any great damage by the mere act of secur¬ 
ing its supply of nourishment, but by injecting a virulent poison into the 
wound, from which its victim languishes, first losing all appetite and gradually 
growing weaker as the poison continues through the system, until complete 
exhaustion is soon followed by death. None of the wild animals of Africa, 
however, suffer from its attacks, a fact which naturalists have not been able to 
account for. It is never met with outside of a small district near the centre 
of Africa, and even in this restricted region it is not always to be seen, even 
though there be domestic animals to attract it. 
There are yet other species of the fly which mine into leaves, burrow 
into fruits, and dig into the stems of plants. The cheese-mite is a pronounced 
black in color, and has the four hinder-legs yellow. From their power of leaping 
they are popularly called “ skippers.” Some mites live in wine, alcohol, or salt 
water. Some of them are roasted by certain tribes of Indians and are said to 
make a not unpalatable dish. 
The Flea, as a guerilla, is unrivalled; agility, caution, persistency—these 
amiable qualities does he employ to the discomfort of those whom he persecutes 
with his attentions. He is the foe of the household, for not content with covet¬ 
ing his neighbor and his neighbor’s wife, his son and his daughter, he insists 
also upon the pets of the household and some of the animals of the field. 
Troublesome throughout the United States, and specially numerous in sandy dis¬ 
tricts, it is yet far from being the pest which it is in France, Spain and Italy. 
Laying from eight to twelve eggs, these are hatched in the brief space of five 
days, and in fourteen days the small grubs pass into the stage of chrysalis ; 
after yet sixteen days more they spring forth, like Minerva, fully armed, and at 
once enter upon the duties of active life. Fleas have been trained to work in 
harness, but though able to draw one hundred times their own weight, their 
avoirdupois is too slight to have converted them into useful beasts of burden. 
The scientific name for the flea is pulex irritans. It is wingless, body com¬ 
pressed, eyes small and round, legs stout and strong. Its eggs are laid in the 
hair. The larval and pupal stages are each about fourteen days in duration. 
In the West Indies and in South America a species called the chigre (or jigger) 
causes great trouble by burying itself under the nails of the foot. There is also 
a species of chigre , common to this country, which burrows into the flesh, and 
though scarcely larger than a pin-point, is so poisonous as to produce intense 
irritation and great swelling of the parts bitten. If this insect were so large 
as a common tick, with an equal increase of venom, its bite would produce death, 
since nothing in nature is supposed to be more poisonous, and small as it is 
its burrowing has been known to produce a dangerous inflammation. 
