A NATURALIST IN BRAZIL 



nose. He pressed his body closer to his booty; the mouth reached 

 forward, right and left, until half the mouse had disappeared ; then 

 the snake lifted his head, and one saw that the neck was laid in 

 coils, pressing the body down; the mouth remained open, since it 

 had nothing to chew, and so the victim slipped down, until at last 

 the tail disappeared as though of its own volition, so that it looked 

 as though the mouse was voluntarily entering the dark gullet. At 

 last all was over, except for several yawns, and the robber lay still, 

 while in his body the swelling which marked the position of the 

 mouse moved slowly backwards. 



The habits of the snakes are adapted to the habits of their prey. 

 The Sucury, the Giboya, and the venomous snakes hunt mammals, 

 and as these — and especially the smaller species — are nocturnal in 

 habit, the snakes in question go about their business by night. The 

 eyes of both these groups, with their long, vertical pupils, betray 

 the fact that their visual organs are adapted to the darkness. But 

 since their victims might quickly disappear in the darkness, they 

 must somehow be prevented from making the attempt. The 

 Sucury and Giboya prevent their escape by surrounding them 

 with their coils; the venomous snakes by injecting their deadly 

 poison. 



The harmless snakes — with the exception of the Boas and Ana- 

 condas — have large, round eyes, adapted to use by day; their very 

 expression seems to us innocent. The round eye, and the tail that 

 gradually tapers to a sharp point, enable us at once to distinguish 

 the harmless Goral-snake (Plate 31, 10, 11) from the venomous 

 species. The latter (Plate 31, 12) has a fat, truncated-looking tail, 

 and its eyes are very small, lest it should injure them while burrowing 

 in the ground — in search, as a rule, of other snakes. 



A snake which one often exhumes while excavating the nests of 

 the Sauva ants is the "Two-headed Snake," the "Cobra das duas 

 cabe9as" (Plate 31, 8). This creature looks like a very large white 

 earthworm. Because when alarmed it curls its tail up to its head, 

 the Brazilian countryfolk believe that it has two heads, both of 

 which are venomous, and that it bites first with one and then with 

 the other. In reality the snake is perfectly harmless ; indeed, it is 

 not really a snake at all, but belongs to the Lizards; to a group 

 which has lost its feet, like our Blindworm or Slowworm. Neverthe- 

 less it has been given a bad name, and has suffered under it, just 

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