356 THE ZOOLOGIST. 



second, that of probabilities; and the third, that of dreams,"* 

 By the term " Demonstrable " is implied all those instances 

 where protection, absolute or partial, has been or can be demon- 

 strated by experiment or actual observation. " Suggested or 

 Probable " should, however, be applied to those examples where, 

 because we see similarity of structure, markings, or colour, we 

 assume — and probably often correctly — that protection is involved, 

 though no direct knowledge of the same is obtainable. As an 

 illustration, we know that certain Diptera, Eristalis spp., resemble 

 Bees, and we conclude that this simulation has arisen by evolu- 

 tionary means for protective purposes. It must nevertheless be 

 remembered that the Bee itself is not absolutely protected by its 

 sting, and does not possess a corresponding immunity from the 

 attacks of all its enemies. Mr. Woodford, on Peel Island, Moreton 

 Bay, observed Bees of the genus Bombus caught and devoured by 

 Spiders.f Prof. Lloyd Morgan's experiments, however, demon- 

 strate protection at least from birds: — "To another group of 

 chicks I just gave Hive Bees, which were seized, but soon let 

 alone, and then the Droneflies (Eristalis), which so closely mimic 

 the Hive Bee. They were left untouched. Their resemblance 

 to the Bees was protective." + Frank Buckland relates: — "A 

 gentleman in Oxfordshire had a hive of Bees in the cavity of a 

 wall. A common Toad which had taken up its residence in a 

 hole close by was observed to walk forth and place himself at the 

 mouth of the hive, and so catch the Bees in their coming from 

 and returning to the hive with much dexterity and activity. After 

 witnessing the Toad at work for some time, and feeling convinced 

 that, if his depredations were suffered, he would eventually destroy 

 the whole hive, the owner of the Bees killed the robber, and on 

 inspecting his stomach it was found full to repletion of dead 

 Bees."§ 



* ' Philosophical Dialogues and Fragments,' Eng. Transl., p. 5. 



f 'A Naturalist among the Head-hunters,' p. 70, note. 



I ' Habit and Instinct,' p. 52. 



§ ' Curiosities Nat. Hist.,' pop. edit., vol. i. pp. 42-3. — According to Mr. 

 Pocock, and as a result of an experiment, a Spider treats both Bee and 

 Eristalis with the same caution when found in its web ('Roy. Nat. Hist.,' 

 vol. vi. p. 62). That the Bee has no special immunity is attested by Mr. 

 Pickard-Cambridge, who states that another hyinenopterous insect, Philan- 

 thus trianguluiu, in its larval condition feeds upon the Honey Bee. " Since 



