258 LIFE : OUTLINES OF GENERAL BIOLOGY 



very difficult to understand how a percentage of terns can find their 

 way back to their nests when transported in closed baskets to 

 unknowTi waters outside their migrational range, and from a dis- 

 tance of 800 miles. It is possible that a much-needed clue to homing 

 in higher animals might be obtained by the patient and sceptical 

 study of the orientating achievements exhibited by cats and dogs, 

 and some other mammals. 



At present it seems probable that homing in lower animals is the 

 outcome of experience, while that of higher animals depends on 

 innate endowment. Thus it is interesting to recall the fact that 

 when the queen humble-bee has found a suitable nesting-place, she 

 is careful to take her bearings so that she can find her way back 

 after a flight. Here we may quote an instructive passage from 

 Mr. F. \V. L. Sladen's Humble Bee. "The queen crawls round 

 the entrance, and poises herself towards it as she takes wing. 

 Then she rises slowly, and taking careful notice of all the sur- 

 roundings, describes a series of circles, each one larger and swifter 

 than the last. So doing she disappears, but soon she returns and 

 without much difficulty rediscovers the entrance. Similar but less 

 elaborate evolutions are made at the second and third departures 

 from the nest, and soon her lesson has been learnt so well that her 

 coming and going are straight and swift." We cite this passage 

 from an experienced obser^'er because it suggests that the homing 

 power in insects is different from that in birds and mammals. 

 Terns, as we have mentioned, will return from their liberation in 

 unknown seas hundreds of m.les away. A cat, taken by train from 

 Fife to Ayrshire, has found its way home. In such cases — and they 

 are typical — there is no question of mastering tlie topography. 



Some data for horses have been recently forthcoming. A two- 

 year-old horse taken to a new place at some distance late in the 

 evening, in part in darkness, found its way home next morning. It 

 seems that a horse can find its way home in wild Australian country 

 from a distance of 50 miles. There is abundant evidence that in 

 thick darkness or in fog some horses may be trusted to find their 

 way home. Sometimes they have proved to be right when their 

 master thought they were quite wrong. In estimating the data there 

 should be in the first instance a ruling out of all cases of habituation, 

 for this complicates the issue. Moreover, every rider and driver 

 knows that horses have a keen topographical memory. They register 

 difficulties and peculiarities of a road, even when their experience 

 of it is very slender. The most interesting data relate to homing from 

 a new place at a considerable distance, and it would be interesting 

 to find out how many tcntatives or even mistakes the clever creature 

 makes. It would be of great interest to make the crucial experiment 

 of transporting the animal in a horse-box during the night, and then 

 observing if it made for home. 



