LITERARY NOTICES. 



Parker, G. H. The Skin and the Eyes as Receptive Organs in the Reactions of Frogs to Light. 

 Amer Jour, of Physiol. ,Vo]. lo, pp. 28-36. 1904. 



Professor Parker has shown that Rana pipiens is positively phototropic to 

 intensities of light from i to 20,480 candle-metres, and also that the skin as well as 

 the eye is a receptive organ for light. The central nervous system is not directly 

 stimulated. r. m. y. 



Hunter, George "William. Notes on the Heart Action of Molgula manhattensis (Verrill). Amer. 

 Jour, of Physiol., Vol. 10, pp. 1-27. 1904. 



In this study of the heart action of Molgula the author has collected data con- 

 cerning the normal action of the organ, its relation to the nervous system, and the 

 influence ot poisons. Removal of the ganglion in various ways causes modifica- 

 tion of the beat — depression, irregularity, lack of coordination. r. m. y. 



Wixon, Howard H. The Principles of Soaring Flight. Scientific American Supplement, No. 1 554, 

 p. 24904, Oct. 14, 1905. 



The writer attempts to account for the energy acquired by birds when soaring 

 in circles, upon a principle much like that of the anemometer. When in that part 

 ot the circle in which it moves with the wind, the bird tilts its wing anterior edge 

 down, thus presenting a hollow surface to windward and catching the air just as 

 does the cup of an anemometer. But in the other half of the circle, in which the 

 bird is returning against the wind, the wing is tilted in such a way as to offer much 

 less resistance to the passage of the air. 



Observations are needed to show that birds actually make such wing move- 

 ments when soaring in circles. And an elaboration of the theory is needed to show 

 how a bird has power to change its course when drifting before the wind, for at 

 such a time the bird may be motionless with respect to the wind. But the reviewer 

 believes that such an extension of the theory can easily be made, and that Mr. 

 \\ IXON has given a suggestion which, when followed out, will go far toward explain- 

 ing how birds soar in a spiral. Wallace craig. 



Wheelock, Irene G. Regurgitative Feeding of Nestlings. The Auk, N. S., Vol. 22, pp. 54-70. 1905. 

 This article- gives in condensed form the results of observations upon one hun- 

 dred and eighty-seven broods of birds belonging to a wide range of species. The 

 general fact brought out is that every brood hatched in a naked or semi-naked 

 condition was fed by regurgitation for a period varying from one day to four weeks, 

 while those species which are hatched with a covering of down were usually given 

 only fresh food. Wallace craig. 



Breninger, Geo. F. Are the Habits of Birds Changing? The Auk, N. S., Vol. 22, pp. 360-363, 

 Oct., 1905. 



1 he author details changes in the nesting sites of half a dozen American birds 

 following upon the changed conditions due to advancing civilization. 



WALLACE CRAIG. 



