Expenditure 

 Experiment 



SCIENTIFIC SIDE-LIGHTS 



234 



parison with the few that reach maturity. 

 In other cases the paucity of the flowers 

 that are impregnated may be due to the 

 proper insects having become rare under the 

 incessant changes to which the world is sub- 

 ject; or to other plants, which are more 

 highly attractive to the proper insects, hav- 

 ing increased in number. We know that cer- 

 tain orchids require certain insects for their 

 fertilization. ... In those cases in 

 which only a few flowers are impregnated 

 owing to the proper insects visiting only a 

 few, this may be a great injury to the plant; 

 and many hundred species throughout the 

 world have been thus exterminated, those 

 which survive having been favored in some 

 other way. On the other hand, the few seeds 

 which are produced in these cases will be the 

 product of cross-fertilization, and this, as we 

 now positively know, is an immense advan- 

 tage to most plants. DARWIN Fertilization 

 of Orchids, ch. 9, p. 281. (A., 1898.) 



1139. EXPERIENCE, BEES LEARN- 

 ING BY Defense against Deaths-head Moth. 

 Huber first noticed the remarkable fact 

 that when beehives are attacked by the 

 death's-head moth the bees close the en- 

 trance of their hive with wax and propolis 

 to keep out the marauder. The barricade, 

 which is built immediately behind the gate- 

 way, completely stops it up only a small 

 hole being left large enough to admit a bee, 

 and therefore of course too small to admit 

 the moth. Huber specially states that it 

 was not until the beehives had been re- 

 peatedly attacked and robbed by the death's- 

 head moth, that the bees closed the entrance 

 of their hive with wax and propolis. Pure 

 instinct would have induced the bees to pro- 

 vide against the first attack. Huber also 

 observed that a wall built in 1804 against 

 the death's-head hawk-moth was destroyed 

 in 1805. In the latter year there were no 

 death's-head moths, nor were any seen dur- 

 ing the following. But in the autumn of 

 1807 a large number again appeared, and 

 the bees at once protected themselves against 

 their enemies. ROMANES Animal Intelli- 

 gence, ch. 4, p. 184. (A., 1899.) 



1140. EXPERIENCE INCLUDES THE 

 LAWS OF MIND Instantaneous Perception 

 May Teach Eternal Truth. But if " experi- 

 ence " is to be upheld as in any sense the 

 ground and basis of all our knowledge, it 

 must be understood as embracing that most 

 important of all kinds of experience in the 

 study of Nature the experience we have of 

 the laws of mind. It is one of the most cer- 

 tain of these laws, that in proportion as the 

 powers of the understanding are well de- 

 veloped, and are prepared by previous train- 

 ing for the interpretation of natural facts, 

 there is no relation whatever between the 

 time occupied in the observation of phe- 

 nomena and the breadth or sweep of the con- 

 clusions which may be arrived at from them. 

 A single glance, lasting not above a moment, 

 may awaken the recognition of truths as 



wide as the universe and as everlasting as 

 time itself. ARGYLL Unity of Nature, ch. 4, 

 p. 86. (Burt.) 



1141. EXPERIENCE, LEARNING BY, 

 A PROOF OF MIND This proof [of the ex- 

 istence of mind] is in all cases and in its 

 last analysis the fact of a living organism 

 showing itself able to learn by its own indi- 

 vidual experience. Wherever we find an ani- 

 mal able to do this we have the same right 

 to predicate mind as existing in such an ani- 

 mal that we have to predicate it as existing 

 in any human being other than ourselves. 

 ROMANES Animal Intelligence, int., p. 7. 

 (A., 1899.) 



1142. EXPERIENCE THE FOUNDA- 

 TION OF REMEMBRANCE- Phenomena have 

 absolutely no power to influence our ideas 

 until they have first impressed our senses 

 and our brain. The bare existence of a past 

 fact is no ground for our remembering it. 

 Unless we have seen it, or somehow under- 

 gone it, we shall never know of its having 

 been. JAMES Psychology, vol. i, ch. 1, p. 4. 

 (H. H. & Co., 1899.) 



1143. EXPERIENCE THE STARTING- 

 POINT OF SCIENCE We are far distant 

 from the period when it was thought pos- 

 sible to concentrate all sensuous perceptions 

 into the unity of one sole idea of Nature. 

 The true path was indicated upward of a 

 century before Lord Bacon's time, by Leo- 

 nardo da Vinci, in these few words : "Comin- 

 ciare dall' esperienza e per mezzo di questa 

 scoprirne la ragione" (commence by ex- 

 perience, and by means of this discover the 

 reason ) . In many groups of phenomena we 

 must still content ourselves with the recog- 

 nition of empirical laws; but the highest 

 and more rarely attained aim of all natural 

 inquiry must ever be the discovery of their 

 causal connection. The most satisfactory 

 and distinct evidence will always appear 

 where the laws of phenomena admit of being 

 referred to mathematical principles of ex- 

 planation. HUMBOLDT Cosmos, vol. iii, p. 

 10. (H., 1897.) 



1 1 44. EXPERIMENT CHANGES PRE- 

 CONCEIVED THEORY Glacier-motion. 

 Agassiz appears to have been the first to 

 commence, in 1841, a series of exact meas- 

 urements to ascertain the laws of glacier- 

 motion, and he soon discovered, contrary to 

 his preconceived notions, that the stream of 

 ice moved more slowly at the sides than at 

 the center, and faster in the middle region 

 of the glacier than at its extremity. Pro- 

 fessor James Forbes, who had joined Mr. 

 Agassiz during his earlier investigations in 

 the Alps, undertook himself an independent 

 series of experiments, which he followed up 

 with great perseverance, to determine the 

 laws of glacier-motion. These he found to 

 agree very closely with the laws governing 

 the course of rivers, their progress being 

 greater in the center than at the sides, and 

 more rapid at the surface than at the hot- 



