286 



POPULAR SCIENCE MONTHLY. 



of American Ethnology has been prosecuted 

 in the study of social organizations, linguis- 

 tics, and decoration, as illustrated in the 

 Indian tribes. The International Exchange 

 Service, instituted in 1852, is still carried on, 

 with 28,008 correspondents on its records, of 

 which 21,427 ai-e foreign. The operations 

 of the Astrophysical O))servatory have con- 

 sisted chiefly in experiments in the holo- 

 graphic analysis of the infra-red solar spec- 

 trum and the preparation of a report thereon. 

 Information has been sought from the insti- 

 tution on all sorts of subjects, and has been 

 furnished, or else the way to get it has been 

 pointed out. 



Dinner in the "Zoo." — The appetites of 

 the twenty-five hundred animals, more or less, 

 kept in the London Zoological Gardens fur- 

 nish a curious field for study ; and the mat- 

 ter of dealing with them is in some cases one 

 of great difficulty. Only one animal — the 

 hog — seems wholly indifferent as to the na- 

 ture and quality of its food, and some species 

 are extremely fastidious. Even the ostrich 

 manifests a choice, and shows no relish for 

 the nails and old iron with which it is cred- 

 ited with regaling itself on the African 

 farms ; and one species, the Somali ostrich. 



accepts only green food, refusing to touch the 

 meat and biscuits of which the South African 

 ostrich is very fond. The giraffe is one of 

 the daintiest of beasts, living in nature on 

 the leaves which it strips from trees, and in 

 the gardens on the best clover hay, crushed 

 oats, bran, and chaff, with fresh green tares 

 and an occasional onion as relishes ; and 

 while it is very fond of fresh, whole apples, 

 rejects one that has been bitten. Some ani- 

 mals are able to change their native tastes 

 and acquire others, vegetarians becoming 

 flesh eaters, and insect eaters turning to 

 fruit and grain — as the kea, of New Zealand, 

 which, once a strict vegetarian, has become 

 very fond of mutton. Animals in the Zoo 

 have to submit to more or less of this, for 

 their native food is often unattainable. 

 Nothing has been found on which the Aus- 

 tralian koala will thrive, but the kangaroos 

 and wallabies take kindly to grass and maize, 

 and breed frequently. Unfortunately, the 

 kangaroos are very subject to gout and corns. 

 The polar bear is happy with horse blubber 

 and plaice, and the crocodiles and alligators 

 are satisfied with raw meat. The apteryx, 

 which at home Hves on worms and larva?, 

 feeds and prospers on imitations carved out 

 of fillet steak. 



MINOR PARAGRAPHS. 



The debate concerning the presence or 

 absence of considerable bodies of water on 

 Mars has taken a new direction, and observ- 

 ers are now looking for optical evidence. If 

 there is any large body of water on the 

 planet, the image of the sun should be seen, 

 when the proper conditions for the phenom- 

 enon exist, reflected from its surface as a 

 fine point of light. No such image has been 

 observed by the astronomers who have bus- 

 ied themselves most with Mars ; and the 

 conclusion is drawn that the planet's store 

 of water is derived from the melting of the 

 polar snows. Mr. Tajdor, of York, believes 

 tiiat there is enough of this to affect the hue 

 of the vegetation, the existence of which is 

 indicated by dark lines and spots. There 

 does not appear to be anything in this theory 

 to preclude the possibility of Mars having a 

 copious supply of rain. 



While admitting that water may be an 

 effective agent in making deposits like loess, 



M. J. A. Udden adduces reasons in the Bul- 

 letin of the Geological Society of America 

 for believing that the loess in the Mississippi 

 Valley was chiefly deposited from the air. 

 It is often found in situations where the 

 agency of water can hardly be predicated, 

 and contains land shells. The universal pres- 

 ence of mineral dust in the atmosphere and 

 its constant settling necessitate its accumu- 

 lation in places where erosion is at a stand- 

 still or does not exceed the rate of atmos- 

 pheric sedimentation ; and the conditions 

 now nearly correspond with this. In me- 

 chanical composition fine wind sediments and 

 loess are largely identical. The loess beds 

 are more uniform in structure than deposits 

 from water can well be; and other features 

 of the loess appear easier to explain if it be 

 regarded as a land deposit. 



The law of wills and inheritance is cited by 

 Isaac F. Russell, in a paper on the Vendetta, 

 as perhaps exhibiting more than any other 



