166 ANIMAL COLOKATION. 



A great number of conspicuous larvae belonging to the 

 Bombyces and BombycoidiB are, on account of tbeir rarity, 

 ^omitted from this list. These experiments may perhaps be 

 made in the future. But it would need a very ardent disciple 

 of Mr. Poulton's to sacrifice, for the purposes of philosophical 

 zoology, the larvae of the rare and beautiful "Merveil du Jour " 

 {Diphthera orion) ! 



These experiments certainly bring out the fact that the "likes 

 and dislikes of insect-eating animals are purely relative." 

 They are a further proof of the old saying that " one man's 

 meat is another man's poison." They perhaps also show that 

 birds are more fastidious in their taste than either lizards or 

 monkeys. But none of these experiments are thoroughly satis- 

 factory : it is so difficult to interpret them, and they are often 

 contradictory, for a bird will eat one day what it has refused 

 before.* The experiments that have been made are like most 

 other statistics, — they may be made to prove anything. A 

 careful series of observations upon the contents of the stomachs 

 in wild birds would be the nearest approach to a satisfactory 

 solution of the difiiculty ; but there are obvious objections to 

 this mode of investigation. 



Now tasting, especially of birds, would be quite as dangerous 

 to the caterpillar as swallowing it outright. If rejected by a 

 frog it might certainly be completely uninjured, and it appears 

 that even a very prolonged tasting by a duck may not result 

 in any injury. 



Mr. Poulton has pointed out how very important it is that 

 an uneatable caterpillar should be at once recognised and 

 avoided; owing to the thinness of the body wall which contains 

 the blood under considerable pressure, the slightest injury may 

 prove fatal; for the blood will escape in considerable amount, 

 * Butler, in Ann. and Mag. Xat. Hist. 1890. 



