162 PROCEEDINGS OF THE ACADEMY OP [Jail., 



of showing "that birds are in the habit of eating butterflies and that 

 some butterflies are poisonous or nauseous to them and others not." 

 (33, p. 121.) It niust be admitted also that we require vastly more 

 evidence than we at present possess. But evidence is accumulating 

 steadily, and some of the best has been forthcoming in recent years. 

 I may refer especially to Mr. S. A. Neave's observation (30) on 

 January 12, 1912, of a Wagtail devouring Lycsenid and Pierine 

 butterflies, but rejecting an Acraea, in the bed of a forest stream near 

 Entebbe, Uganda. 



Dr. Skinner, in a more recent paper (34, p. 25) refers to the fact that 

 the Biological Survey of the United States examined fifty thousand 

 bird stomachs and only found butterflies in five of them. Mr. 

 C. F. M. Swynnerton has quite lately thrown much light on this 

 method of investigation (33). He is convinced, as the result of 

 recent work at Chirinda, Gazaland, southeast Rhodesia, "that 

 conclusions based on stomach-examination are likely to be fallacious, 

 unless that examination has been so thorough and minute that even 

 such small objects as the scales of Lepidoptera must have been 

 detected if present, even in small numbers, in either stomach or 

 intestines, unless a very large series has been so examined for each 

 species, and unless, finally, a note had been made at the time of the 

 shooting of each specimen as to the probable proportions in which 

 insects of various kinds were present at the moment." Mr. Swyn- 

 nerton's paper was especially intended as a reply to Mr. G. L. Bates 

 (35), whose statements are quoted by Dr. Skinner (33, p. 122). 

 I have treated this subject very briefly and inadequately because 

 I hope to return to it in a later paper dealing with the attacks made 

 by Mr. W. L. McAtee in a memoir (38) written in a very different 

 spirit from that of Dr. Skinner. 



2. Haase's Name "Pharmacophagus" and his Hypothesis that 



Mimicked Butterflies (Models) derive Nauseous 



Qualities from the Larval Food-plants. 



Dr. Skinner, influenced by my use of Haase's term " Pharmaco- 

 phagus," is apparently under the impression that I am a convinced 

 follower of his hypothesis. This is by no means the case. In a 

 review (14) of Haase's work (13) I expressed the opinion, to which 

 I still adhere, that the hypothesis is probably true — although as yet 

 (juite unproved — for some distasteful species, but that it is certainly 

 not true of others. Rothschild and Jordan (30, 433-4), following 

 Horsfield (l) and Haasc (9), have shown that the PapilioninoB are 



