19 



thoroughly deceived, just as the bird is, and not '• momentarily," as 

 Dr. Longstaif tells us he was. That non-entomologists are com- 

 pletely deceived I have direct evidence. Mr. C. B. Roberts, who 

 collected specimens for me in British Guiana, but who had no 

 knowledge of what he was collecting, did send me one or two wasps 

 of the genus Pi^eiiclai/exia, along with the closely resembling moth 

 Sphecosoma testacea, thinking that they were all moths. I certainly 

 do not think we should credit birds with any greater acumen 

 in the distinguishing of specimens than that of a non-specially trained 

 human being. But if birds are deceived by moths looking like lichen, 

 or wood or leaves, why should thej^ not be deceived by looking like 

 another living thing of their own kind ? Scarcely anyone has ever 

 questioned the resemblance of, say, AifriopU apnlina to the lichen 

 on an oak trunk or the wonderful likeness of the leaf butterfly 

 KalUma inachis when it rests to a leaf. The argament could still 

 be raised as to whether people had seen birds attacking or hunting 

 for the species to such an extent as to cause Natural Selection to 

 operate. One wonders, of all the hundreds of lepidopterists in this 

 country, how many have ever seen birds hunting on tree trunks or 

 on palings for moths, yet in this country we have in the past 20 

 years seen some remarkable changes in some of our indigenous 

 species that are to be found in and around our large towns, and it 

 is almost universally agreed that Natural Selection must have acted 

 on the species with the altered conditions of the insects' surroundings. 

 It should, therefore, be quite conceivable that although we do not 

 often see birds attacking butterflies or moths in the air or at 

 rest, attacks can be both numerous and persistent. But Mr. 

 Marshall while in Rhodesia ("Trans. Ent. Soc.liond., 1902, p. 355), 

 after setting himself to look for and^ note such cases did not by any 

 means find them of rare occurrence, and other observers have since 

 noted cases not infrequently. Quite recently (in the September 

 number of the " Entomologist's Record," vol. xxiii, p. 218) Mr. R. 

 Shelford records a most interesting observation as to a sparrow 

 attacking a I'ieris rapa, and after mouthing it, letting it go. A clear 

 case of experimental attack. The same observer later saw the 

 same bird catch and eat a L'hri/sopa, which to our senses would 

 seem to be most unpalatable. The human standpoint seems, 

 therefore, to be not very reliable when we are considering the 

 tastes of birds. Mr. C. \V. Colthrup ("Ent. Rec," vol. xxiii, p. 218) 

 records a number of instances of ditierent birds eating various 

 butterflies, and now that attention has been drawn to the matter 



