2 JANUARY 1932, Page 18

Some years ago in the park of a country house

ditches and ladders of a sort were substituted for gates to the great convenience of all concerned. The device is simple and effective. This girder-like bridge with rungs in place of a solid centre provide two easy tracks for the wheels of car but were too difficult for animals. The bridged dykes continue to be a quite sufficient barrier against all stock ; but the rabbits, at first too timid to cross, have now learnt the way ; and the young appear to have inherited the requisite knowledge and temerity. As in the avoidance of telegraph wires, races of animals, not only individuals, appear to learn adaptations to such new conditions. The acquired skill is difficult to explain scientifically. Can memory be inherited ? It seems unlikely ; but somehow or other the later stocks avoid or negotiate, by some sort of instinct apparatus that were not at all understood by their ancestors. The railways as well as the telegraph wires killed large numbers of birds at first, and now kill few. Mammals, too, have learned the railways. They are also, I think, developing a road sense, though still it is the pace that kills ; a moderately slow driver seldom kills anything. I should like to hear that the Minister of Transport had ordained a speed limit for the months of May, June and July, when the callow young are about the roads,