PROTECTIVE MIMICRY. 219 



will capture wasps. Although Dr. McCook makes the sugges- 

 tion referred to, be does not accept it as an explanation of the 

 mimicry, and for the following reason. " Those spiders," he 

 says, " which are most frequently found within the clay cells 

 of mud dauber wasps, and those which these insects most 

 frequently collect as food for their larvre, are the Sedentary 

 groups, such as Orbweavers and Lineweavers. They do, indeed, 

 take the Thomisoids, especially those that lurk on flowers 

 in pursuit of prey, and which, in turn, sometimes capture the 

 wasps. The Saltigrades are also taken ; but, if I may judge 

 from my own observations, they are least numerously repre- 

 sented of all the tribes, except perhaps the Lycosids and the 

 Tunnelweavers. This seeming immunity is evidently not due 

 to any likeness of Attidaj in general features to wasps, but 

 simply to their manner of life, which in large measure screens 

 them from assault and enables them to escape. Now, the 

 question must rise, in considering such a theory, " Why does 

 not natural selection operate for the protection of those spiders 

 which obviously need protection the most ? " The most in- 

 genious explanation of this mimicry, on the natural selection 

 theory and it only applies to one instance is the explanation 

 which has been advanced to explain the mimicry of a South 

 African species: the ant feeds upon honey-dew along with 

 quantities of other insects; as the ants are engaged in a peace- 

 ful occupation, they do not interfere with the other insects, 

 which therefore do not fear them. The spider takes advantage 

 of this state of affairs to prosecute its own ends; but this 

 explanation reopens the debated question of insect vision. 



Resemblances between Insects occurring in different Countries. 

 Mr. Herbert Druce has kindly allowed me access to his rich 

 collection of Neotropical Lepidoptera, which furnishes numerous 



