112 SCIENTIFIC ILLUSTRATIONS [Exi 



of the portentous travail will be a gigantic water-snake or huge 

 crocodile aroused from its torpidity. D. 



The Terrific Force of an Evil Thing. 



The lance-headed viper or Trigonocephalus (Bothrops lanceo- 

 latus) is most common in the West Indian Islands, where it is 

 justly dreaded. It has been computed that at Martinique fifty 

 persons out of a population of one hundred and twenty-five 

 thousand souls die annually from the bite of these odious reptiles. 

 Their fecundity is frightful. Every female bears sixty young, 

 which on their very advent into the world are completely 

 formed and able to wound. This viper, unlike the rattlesnake, 

 carries no warning rattle ; nothing indicates its presence. D. 



The Unwisdom of Exaction. 



The llama, or guanaco (Auchenia llama), is found among 

 the recesses of the Andes. In the silver mines his utility is 

 very great, as he frequently carries the metal from the mines 

 in places where the declivities are so steep that neither asses 

 nor mules can keep their footing. The burden carried by this 

 useful animal, the camel of the New World, should not exceed 

 from one hundred to one hundred and twenty-five pounds. If 

 the load be too heavy he lies down, and no force or persuasion 

 will induce him to resume his journey until the excess be re- 

 moved. Thus he teaches us the unwisdom of endeavouring to 

 exact too much from those who are willing to serve us well. 



VT. 



Existence by Instalments. 



There are creatures which possess existence by instalments. 

 "The Vibrio, Kotifer, Macrobiotus, &c., are," says Professor 

 Owen, " organisms which we can devitalise and revitalise, 

 devive and revive, many times." Living together as these sorts 

 of organisms generally do, tenanting the same tufts of moss or 

 the same patches of lichen, they eke out their existence by in- 

 stalments, instead of enjoying a more or less definite and con- 

 tinuous span of life. They possess the power of resuming 



