( xviii ) 



Mr. McLachlan : A point that appeared to him to be a 

 good deal overlooked in this matter was the possibility that 

 two species might go on independently and yet apparently 

 mimic each other by arriving at the same results in their 

 modifications. 



Prof. Weldon, F.R.S. : He did not intend to enter upon 

 the details of mimetic resemblances or upon the theories 

 which had been put forward, but, speaking as a visitor, he 

 would like to take the opportunity, as he did whenever an 

 occasion presented itself, of pointing out to entomologists 

 that the truth or falsity of these theories was capable of being 

 tested to a large extent experimentally, and especially by 

 experiments which would give a basis for statistical deter- 

 minations. 



Thus, if one took a mimetic species distributed over a 

 large area, homoeochromatic with one species in one district, 

 and with another in another district, such a species on 

 theoretical grounds must be variable and susceptible to a 

 moderately rapid selective action. 



In any given area, although the examples caught might 

 conform fairly closely with a common type, the species must 

 still be variable and capable of selection ; if the theories were 

 true there should be evidence of continued selective destruc- 

 tion, and this could be ascertained by experimental breeding 

 on a large scale from eggs of wild individuals. A comparison 

 of the examples thus reared with an equal number of wild 

 specimens from the same locality would show whether there 

 was any greater variability among the bred forms. Assuming 

 that sources of error had been excluded, such a result would 

 be good evidence of the existence of continued selection 

 tending to ensure conformity with the model. 



Mr. J. J. Walker : He was unable to believe that birds 

 were effective agents in causing mimetic resemblances. 

 During all his experience as a collector in different parts of 

 the world he had never seen a bird pursue and catch a 

 butterfly but once. On the other hand, butterflies were often 

 eaten when at rest by lizards, small mammals and monkeys. 



Col. Yerbury : During his personal experience of many 

 years in India and Ceylon he had hardly ever seen a bird 



