604 THE POPULAR SCIENCE MONTHLY. 



Strawberries are a choice delicacy for the wood-hen, and their seeds 

 are minute enough to escape being ground up among the millstones of 

 its crop. The fowls, therefore, unknowingly sow the seeds in the for- 

 est along with their dung, and help the plant to find new beds in fresh 

 soil. Geese are especially fond of the leaves of Potentilla anserina, 

 and with them eat multitudes of the minute seeds of the plant. There- 

 by, while the natural home of the potentilla is by brooks, it is trans- 

 planted by the geese to quite different localities ; and in mountain- 

 regions, where nearly all the towns are on little streams, the potentilla 

 is to be found as far away in the neighboring fields and along the 

 borders of the woods as the geese are driven in the fall to feed upon 

 the stubble. 



When the Spaniards settled in Chili they brought with them their 

 native apple and other fruit-trees. The fruits of these orchards, which 

 were planted, of course, only in the neighborhood of dwellings, were 

 fallen upon by the native parrots, and they carried the apples and un- 

 digested seeds into all parts of the country, so that the traveler may 

 now find whole forests of wild apple-trees in places which have re- 

 ceived no other touch of human cultivation. In a similar way crows 

 have spread the opuntia over the uninhabited islands of the Canaries, 

 and the nut-crackers in the Alps the seeds of the vetch in places where 

 the winds and man could never have carried them. 



Not a few birds are impelled, by the instinct to get their food in as 

 much security as possible, to form relations with other animals. Star- 

 lings are found frequently associated with flocks of sheep, making 

 themselves at home on their backs and playing the part of selfish bene- 

 factors of the suffering animals as they explore their wool for appetiz- 

 ing ticks and lice. So there are birds, according to eminent travelers, 

 in Africa that perform similar service for elephants, camels, horses, the 

 rhinoceros, and the hippopotamus. These prudent and vigilant birds 

 are ever to be found in company with their huge providences, and 

 give the sleeping monsters timely warning, with their shrill, familiar 

 cries, of approaching danger. Lichtenstein relates that ostriches and 

 zebras are on good terms with one another, to their mutual profit. 

 The droppings of the zebra afford a breeding-ground for innumerable 

 beetle-grubs, and these are a choice delicacy to the ostriches. When 

 any danger approaches the company — if, for instance, a horseman ap- 

 pears in the distance — it is at once perceived by the tall, sharp-eyed 

 birds, which take to flight in a direction away from the threatening 

 object ; and the dull-sighted zebras, without knowing what is really 

 going on, sagaciously intrust themselves to the guidance of their care- 

 ful associates. Similar harmonies in behavior may be observed among 

 animals in very remote quarters of the world — between the rheas and 

 the stags and guanacas of Brazil, and between the royal pheasant and 

 the wild goat of the Caucasus. The ancients had a story of a bird 

 — the trochilus — which made its living by picking the teeth of the 



