348 SCIENTIFIC ILLUSTRATIONS [Tea 



coral rock from one part of the world to another ; its currents 

 receive them from the rivers and hand them over to the little 

 mason for the structure of the most stupendous works of solid 

 masonry that man has ever seen the coral islands of the sea. 



T. 



The Fascination of Terror. 



Over some natures terror exercises an inexplicable fascination. 

 Under its influence they are betrayed into the very jaws of 

 danger. They remind us of the tree-serpents and the birds. 

 The boom slange (Bucephalus capensis), a species of tree-serpent, 

 is generally found upon trees, to which it resorts for the purpose 

 of catching birds, upon which it delights to feed. The presence 

 of a specimen in a tree is generally soon discovered by the 

 birds in the neighbourhood, who collect around it, and fly to and 

 fro, uttering the most piercing cries, until some one, more terror- 

 struck than the rest, actually scans its lips, and almost without 

 resistance becomes a meal for its enemy. During such a pro- 

 ceeding the snake is generally observed with its head raised 

 about ten or twelve inches above the branch round which its 

 body and tail are entwined, with its mouth open, and its neck 

 inflated, as if anxiously endeavouring to increase the terror which 

 it would almost appear it was aware would sooner or later bring 

 within its grasp some one of the feathered group. MU. 



A Fallacious Test. 



Man frequently satisfies himself that he has come to an 

 accurate conclusion merely because on the application of what 

 he considers an infallible test he discovers a particular antici- 

 pated result. Often enough the test is utterly fallacious. Take 

 an example. The tanghin, or tanguen, is the only plant of its 

 genus, and is confined to Madagascar. Its poisonous seed is 

 esteemed by the natives an infallible criterion of guilt or 

 innocence. After being pounded, a small piece is swallowed by 

 the supposed criminal. If he be cursed with a strong stomach, 

 which retains the poison, he speedily dies, and is held guilty ; 

 if his feeble digestion rejects it, he necessarily escapes, and his 

 innocence is considered proven. Now it is obvious to any 



