CAN ANIMALS TELL THE TIME ?

Evening Star, Issue 19520, 30 March 1927, Page 3

CAN ANIMALS TELL THE TIME ?

WONDERFUL SPARROWS OF THE LUXEMBOURG ■ [By Professor J. Arthur Thomson, in ‘John o’ London’s Weekly.’] : In the Luxembourg Gardens, in ' Pans, sparrows and other small birds 1 used to have the habit of congregating punctually shortly before an early forenoon ..hour, when a benevolent visitor . was wont to give them a big meal of crumbs.’ They seemed to have an accurate sense of time, for they did not wait for his appearance nor for the , clock to strike. They congregated beforehamd so as 1 to be ready for the ; feast, and their punctuality was often ’an occasion for remark. Had they i gathered when they saw him, it would ( nave been a simple case of association: “There’s a figure that spells crumbs.” But the puzzle was the punctual gathering before there was any hint of hos- ■ pitality. ■ OUIt GASTRIC CLOCK. One of the suggestions mads in regard to the sparrow puzzle was that the birds began to feel the pangs of hunger about the same time every morning, and no one would wish to ex- ' elude the idea of constitutional rhythms. The body soon forms a habit, and even in plants there is occasionally some punctuality in the opening and closing of the flowers. When the course of life from day to day is very regularly punctuated there ia some enregistration of this in the body. Thus, the little green Convoluta worms of the Roscoff sands come to the surface at the first splash of the incoming tide, and disappear at once when the last wave of the ebb is passed. And they will continue doing this for a week at the proper time in a tideless aquarium on shore. Similarly there are regularly living men who always know the lunch hour"by their internal sensations; they have a gastric dock. There are others who wake in the morning or in tiio middle of the right with extraordinary puuctuality, because the regular routine of bodily functions starts the alarum clock without fail. It must be allowed that some of the eases where animals seem to know the time are due to constitutional rhythms, to the promptings of internal periodicities of very regular recurrence. SIGNS OF THE TIMES. But without discarding the rhythm theory for the sparrows, we must look for the chief explanation in another direction, which was suggested by the fact that when “summer time” began the birds still congregated punctually as if they could read the clock. They gathered at a quarter to 10 by the clock as usual, though this was really an hour earlier. This seemed almost magical, yet the explanation is probably simple. The work of the gardens, such as sweeping leaves and adjusting seats, went on regularly day after day, and the probability is that the birds established an association between what was going on and the approaching appearance of their hospitable friend. When the change was made to “summer tune” the routine of the garden was-at precisely the same stage as before. It is difficult to prove such a theory without experiment, but various carefullyobserved cases point to the view that animals may seem to tell the tunc Wucn they are simply observing certain signs of the times which have come to have a profitable associative value. A combination of the rhythm’theory and the . association theory may be in many cases quite legitimate.

, WHEN SUNDAY COMES ROUND. Some well-observed and well-criti-cised cases show that clover animals, such as dOgs and horses, alter their routine behaviour on Sunday morning. A dog that lias been proud to run to the railway to retrieve tho newspaper thrown out every morning from the passing train, and has learned to do this perfectly without control and oven without suggestion, will take no steps on Sunday morning, when there is no paper. It has been known to disobey flatly when told to go. In such a case it is unnecessary to suppose that the dog has a sense of the normal “train time,” or a feeling that a week has passed and that Sunday has come round once more. We may bo sure that animals live in ' an" unending “ now.” The dog lias built up an association complex of things going on, and this _ serves it as tho signal of “train time.” On Sunday morning the household routine or the farm routine is interrupted, and the signal, if one may say so, is not sounded. Just as a dog’s mouth may*water when a whistle sounds, because an association has been experimentally built up between the whistle and food, so it is in a measure with the newspaper dog, only the stimulus and the reaction are much more complex. Instead of the whistle there are intricate routine circumstances, and instead of the flow of saliva there is very effective behaviour. Yet all this is only a half-truth; for, in the case of a highly-evolved animal like a dog, educated in responsible partnership with man, there is an active memory and an intelligent grasp of the situation. None the less we do not believe that the dog has any sense of time. Perhaps tho nearest approach to that is to be seen in some alert hunting animals, like the fox, which have been known to wait the reappearance of their prey which has been hidden from view for a short time, for instance, by a stream tunnel running under the road.

THE PUNCTUAL PALOLO WORM. There is a certain kind of sea urchin it Suez which spawns regularly at the nil! moon, as Mr Muuro Fox has ihowu, but no one as yet understands row the periodicity has been established or what pulls the trigger with such precision. Much more striking, however, is the regularity with which the various Palolo worms crawl backwards out of the hoick in the coral reefs and break off their body Close behind the head. The bodv is full of eggs and sperms,, which are shed in the water; the head creeps back into the reef, and gradually grows another body, to be set adrift precisely a year afterwards. In ■ the Japanese Palolo worm this extraordinary spawning takes place every year on the night before either the new or tho full moon in the middle _or latter, half of December. It invariably occurs at midnight just after the flood tide, and by 2.15 the water, which was like vermicelli soup with crowds of wriggling, bursting, headless worms a couple of hours before, is once more clear. Animals cannot tell the time, hut they are often wonderfully timed.