Publications Reviewed. 63 



after, powers which no other birds in this part of the world are 

 known to display, and whidh must be regarded as preparatory to 

 the climbing stage soon to follow." 6. The development of the 

 quill stage of the definitive feathers and the preening instinct on 

 the sixth day results in the unfolding of the larger feathers centri- 

 petally from their tips on that day. 7. " Fear is attuned to the 

 climbing stage and not to flight .... and matures with compara- 

 tive suddenness on the sixth day, or shortly before the bird is 

 ready to climb." 8. " Parental instincts are as strong in the Amer- 

 ican cuckoos as in thrushes or in passerine birds generally, and 

 there is more indication of retrogression to parasitism in the 

 former than in the latter." 9. The nests are adequate. 10. " When 

 disturbed in its nest-activities, the black-bill has been known to 

 transfer its eggs to a new nest of its own, an action which strongly 

 suggests the practice of the European cuckoo of carrying its laid 

 egg in the bill to the nest of a nurse." 11. "The American spe- 

 cies occasionally ' exchange ' eggs, or lay in other birds' nests, 

 and when so doing the black-bill has been known to struggle for 

 possession of the stolen nest. Since similar actions have been 

 repeatedly observed in one or another degree, in numerous spe- 

 cies, in which no suspicion of parasitism exists, and in all parts 

 of the world, they must be ascribed, in addition to the reasons 

 given above, not to " stupidity or inadventance," or " a tendency 

 toward parasitism," but to temporary irregularities in the rythm 

 of the reproductive cycle. 



This paper represents the sort of intensive study which we must 

 more and more be looking toward if our knowledge of the birds is 

 to progress at anywhere near the same rate in the next score of 

 years that it tias in the last score. We particularly commend 

 the field studies in the natural environment of the birds instead 

 of laboratory studies under control. Tbe latter has its important 

 place, of course, but the former has been too much replaced by 

 the latter up to the present time. 



On the Olfactory Organs and the Sense of Smell in Birds. By 

 R. M. Stron. From the Hull Zoological Laboratory, University of 

 Chicago. Reprinted from The Journal of Morphology, Vol. 22, 

 No. 3, September, 1911, pp. 619-660. 4 text-figs., 2 pis. 



This paper is the result of a series of carefully conducted ex- 

 periments with ring doves placed in a labyrinth where various 

 odors were employed to test their olfactory sense, supplemented 

 by studies of and dissections of the olfactory lobes and nerves and 

 the nasal chambers, on the part of the author, and an exhaustive 



