374 Recent Literature. [j^jy 



the natural selectionist might be that at some previous time such adapta- 

 tion had held, and this of course is unanswerable since we have no way of 

 knowing what host plants may have been the home of the insects in bygone 

 periods; but it is interesting to note that the genera Ceresa and Telamona, 

 which now show little protective resemblance to parts of their hosts, are 

 more numerous and apparently maintain an existence with greater ease 

 than do those species that show very excellent protective resemblances. 



"It is unnecessary to take up separately each of the local forms in this 

 respect. For each it is possible to suggest an explanation, reasonable or 

 otherwise according to the degree of imagination possessed. But in general 

 it must be said for the local forms, as for the family as a whole, that such 

 speculation merely lies in the realm of conjecture." (pp. 419-20). 



The realm of conjecture is a vast domain, illimitable in fact, otherwise 

 we should have, under the necessity of inventing a new infinity, to accom- 

 modate the unrestrained theorizing of the selectionists. Contact with 

 the hard facts of what adaptations do and do not accomplish invariably 

 removes the young and plastic naturalist from the thrall of protective 

 adaptation doctrine. The reviewer has watched the course of this process 

 in a number of cases of men beginning the work of analyzing the contents 

 of bird stomachs. First, surprise is manifested that birds should eat things 

 that college teaching has pronounced protected, then as other cases occur 

 from time to time the old belief is entirely cast aside, and finally long expe- 

 rience leads to the conclusion that in their respective ecological niches birds 

 feed practically indiscriminately. 



To return to the Membracids, we must conclude that their protective 

 adaptations have no especial significance in foiling predators. In Biological 

 Survey investigations tree hoppers have been found in the stomachs of 

 more than 120 species of birds, and in numbers up to 26 individuals in a 

 single stomach. They have been found in 15 or more stomachs of each 

 of the following species: Great-crested and Ash-throated Flycatchers, 

 Meadow-lark, Brewer's Blackbird, Bullock's Oriole, English Sparrow, Cliff 

 Swallow, Red-eyed, Solitary and Warbling Vireos, Bush-tit, and Ruby- 

 crowned Kinglet. The tree hoppers identified belong to 21 different 

 genera indicating that no partiality is shown. Membracids with the 

 most prominent horns and spines of any in our fauna, as those of the 

 genera Campylenchia, Platycotis, Ceresa and Platycentrus are taken with the 

 rest.— W. L. M. 



The Ornithological Journals. 



Bird-Lore. XX, No. 2. March-April, 1918. 



Some Notes on Martin Colonies. Five contributions from as many 

 writers. 



Notes on the Tree Swallow. By Verdi Burtch. ' 



The Song Sparrow. A Poem by Edw. J. Sawyer. 



How to Make and Erect Bird-Houses. By Hubert Prescott. 



