Correspondence 159 



grass ill c-losc proximity to the nest, where they \\ere uiider observation. 

 In a few instances the Mayflies were counted as they were being gathered. 

 On this date 244, counted, Mayflies were fed to the young. 



Usually the old bird pauses an instant at tlie nest before feeding, 

 during which time there is au excellent opiiortunity for counting. In 

 fact, Mr. Gabrielson tells me that this summer, while watching a Eose- 

 breasted Grosbeak's nest, he was able, by making a slight noise, to hold 

 the male on the edge of the nest for three minutes, by the watch, while 

 trying to determine the contents of its beak. I wish I might assure the 

 critic that it is not surprising for the bird to have so many Mayflies in its 

 beak; neither is it, under the circumstances, particularly difficult to 

 count that number of them. 



The ants may be discussed in a similar way. I think no more than 

 three ants were recorded at any single visit. In all of these records, it 

 is understood, I had supposed as a matter of course, that the number 

 recorded were seen and counted; but it was not claimed, nor was it in- 

 tended to convey the impression, that no more were in the bird 's bill. 

 For instance, if the old bird visits the nest with a beak full of ants, 

 and the observer could distinguish the bodies of three individuals, it 

 would be ridiculous to assume that no more than three were in the 

 bird's mouth. This is so elementary! 



It will be found that in Gabrielson 's report on the Brown Thrasher 

 study, in Table I, the plus sign was frequently used to indicate that a 

 certain number of individual insects were recognized out of a larger 

 number. In this report (Wils. Bull., XXIY, June, 1912, p. S4) there will 

 be found the following statement : "It Avill be noticed in the tabulated 

 data that the number of insects was not always determined exactly, but 

 was entered in this manner, '6+ Mayflies,' etc. In all such cases 

 the minimum number was used in computing the tables. As all of the 

 persons who assisted were cautioned especially to note the number of 

 insects exactly, it is safe to assume that if there be any error in the data 

 it is in having recorded too few insects, rather than too many. ' ' 



The reviewer then believes he has given sufficient illustrations of the 

 inaccuracy of the work to demolish it completely, and proceeds with this 

 ex cathedra pronouncement : "It should be recognized that reporting on 

 the food of nestling birds on the basis of field observation is work for 

 accomplished entomologists, not for amateur ornithologists, ' ' with em- 

 phasis, perhaps, on the "amateur." Of course, no one will dispute this 

 statement, although the work is more likely to be done by an ornitholo- 

 gist who knows some entomology, than by an ' ' accomplished entomolo- 

 gist." The only fault with such a remark is the animus revealed by it, 

 which does not beget confidence or friendliness. The reviewer is expected 

 to give more conclusive proof of inaccuracy before indulging in such 

 caustic comment. 



The very excellent pioneer report on the nest study of the Chipping 



