cciv GENERAL SUMMARY OF SCIENTIFIC AND 



of Mexico. The true vultures do not exist at present in the 

 Western hemisphere, and the present determination adds 

 one more Old World type to the extinct fauna of the United 

 States. The genus Vultur is now associated in Africa and 

 India with Rhinoceros, camels, horses, etc., as in the period 

 of the late tertiary in New Mexico. 



A new work on the locomotive apparatus of birds, by M. 

 Alix, contains a careful study of the skeleton and muscular 

 system. 



The subject of instinct in birds and mammals has again 

 been discussed by Mr. Spalding in Nature. He claims that 

 the instincts of animals appear and disappear in such season- 

 able correspondence with their own wants and the wants 

 of their offspring as to be a standing subject of wonder. 

 They have by no means the fixed and unalterable character 

 by which some would distinguish them from the higher fac- 

 ulties of the human race. It is a common practice to hatch 

 duck's eggs under a hen, though in such cases the hen has 

 to sit a week longer than on her own eggs. Mr. Spalding 

 tried an experiment to ascertain how far the time of setting 

 could be interfered with in the opposite direction. Two 

 hens became broody on the same day, and he set them on 

 dummies. On the third day he put two chicks a day old to 

 one of the hens. She pecked at them once or twice, seemed 

 rather fidgety, then took to them, called them to her, and 

 entered on all the cares of a mother. The other hen was 

 similarly tried, but with a very different result. She pecked 

 at the chickens viciously, and both that day and the next 

 stubbornly refused to have any thing to do with them. 

 Birds, he maintains, do not learn to fly. On shutting up 

 five unfledged swallows, they flew when liberated as well as 

 the old ones. Such he found to be the case with titmice, 

 tomtits, and wrens. With man, as in the lower animals, 

 Spalding believes that the progress of the infant is but the 

 unfolding of inherited powers. " With wings there comes 

 to the bird the power to use them ; and why should we be- 

 lieve that because the human infant is born without teeth, it 

 should, when they do make their appearance, have to dis- 

 cover their use by a series of happy accidents?" In com- 

 mon with other evolutionists, Spalding believes that " in- 

 stinct in the present generation may be regarded as the 



