^°\^f^-^] Recent Literature. 121 



nologist in the country. Gentry records several species of lepidopterous 

 larvae as food of nestling Chimney Swifts and Nighthawks, when in fact 

 the food of the young of these species does not vary appreciably from that 

 of the adults and the latter take very few caterpillars. 



Twenty species of insects are recorded as food of the Olive-sided Fly- 

 catcher, a rare species in eastern Pennsylvania, almost as long a list as the 

 Biological Survey has been able to accumulate from an examination of 

 63 stomachs. Suspiciously full notes are given for such rare species (in 

 Pennsylvania) as the White-winged Crossbill, Mourning, Connecticut, 

 and Cerulean Warblers. We may inquire also into his statements as to 

 the occurrence of the birds themselves. For instance he says (Vol. I, p. 

 311) of the White-crowned Sparrow, '' from the 20th of April to the middle 

 of May it congregates in flocks of a dozen or more .... Whilst writing. 

 May 4, vast numbers are daily observed within our gardens and the adjoin- 

 ing fields." The facts are that this sparrow is rare everj^where east of 

 the Alleghenies, and probably never have vast numbers been seen about 

 Philadelphia. 



If this work of Gentry's were scientifically accurate, it would now rank 

 as a classic. But regarded with suspicion at first and latterly ignored, its 

 most obvious defect is that it looks too good. Gentry even claims to have 

 identified the eggs and pupaj of certain species of Cratonychus (now 

 Melanotus), a thing which is to-day impossible for even the best coleopter- 

 Lsts. 



The ' Life-Histories of the Birds of Eastern Pennsylvania ' must be 

 known then as a dangerous mixture of fact and unfact. Its accuracy in 

 some respects gives it a deceptive appearance of verity, but with regard 

 to the records of bird food jt is certain that the only safe course is to regard 

 them as almost entirely products of the author's imagination. — W. L. M. 



African Econoinic Ornitholog^y. — An important paper by Austin 

 Roberts distinguishes that writer as a pioneer expounder of the ' Economics 

 of Ornithology in South Africa.' ^ The author considers birds in relation 

 to grain, fruit, poultry, and stock, and also gives a list of scavengers, and 

 of birds suggested for protection. Mr. Roberts says: " Before the advent 

 of white men in South Africa birds affected even the primitive agriculture 

 of the natives; the patchy fields of corn had to be guarded against the 

 same granivorous birds which now trouble us. But the conditions of that 

 time differed widely from those obtaining now, as the grain fields were 

 small and easily protected .... Soon after the settlement of the country 

 by white men a new feature arose in the introduction of cultivated fruit. 

 Frugivorous birds, formerly dependent upon the precarious suppUes of 

 Nature, soon learned to appreciate the better quality and greater quantity 

 placed within their reach, and it is not surprising that they forsook the 



1 Agr. Journ. Union of S. Africa, I, No. 3, April, 19H, pp. 352-369. 



