Decay 

 Degeneracy 



SCIENTIFIC SIDE-LIGHTS 



152 



is taken away that which he hath, and after 

 a few years of parasitism there is nothing 

 left to save. DRUMMOND Natural Law in 

 the Spiritual World, essay 9, p. 302. (H. 

 Al.) 



744. DECIMALS, THE SYSTEM OF, 

 PROVIDED FOR IN CARBONIFEROUS 

 PERIOD Numerical Relations in Nature. 

 The leaves of plants are not arranged at 

 random, but in a series of curiously related 

 spirals, differing in different plants, but al- 

 ways the same in the same species and regu- 

 lated by definite laws. Similar definiteness 

 regulates the ramification of plants, which 

 depends primarily on the arrangement of 

 the leaves. The angle of ramification of the 

 veins of the leaf is settled for each species 

 of plant ; so are the numbers of parts in the 

 flower and the angular arrangement of these 

 parts. It is the same in the animal king- 

 dom, such numbers as 5, 6, 8, 10 being se- 

 lected to determine the parts in particular 

 animals and portions of animals. Once set- 

 tled, these numbers are wonderfully per- 

 manent in geological time. The first known 

 land reptiles appear in the Carboniferous 

 period, and they have normally five toes; 

 these appear in the earliest known species in 

 the lowest beds of the Carboniferous. Their 

 predecessors, the fishes, had numerous fin- 

 rays; but when limbs for locomotion on 

 land were contrived, the number five was 

 adopted as the typical one. It still persists 

 in the five toes and fingers of man himself. 

 From these, as is well known, our decimal 

 notation is derived. It did not originate in 

 any special fitness of the number ten, but in 

 the fact that men began to reckon by count- 

 ing their ten fingers. Thus the decimal sys- 

 tem of arithmetic, with all that follows from 

 it, was settled millions of years ago, in the 

 Carboniferous period, either by certain low- 

 browed and unintelligent batrachians or by 

 their Maker. DAWSON Facts and Fancies 

 in Modern Science, lect. 5, p. 184. (A. B. 

 P. S.) 



745. DECISION TO BE MADE HA- 

 BITUAL Habit of Indecision To Be Avoided 

 Make Nervous System an Ally, Not an En- 

 emy. The great thing, then, in all educa- 

 tion, is to make our nervous system our ally 

 instead of our enemy. It is to fund and 

 capitalize our acquisitions, and live at ease 

 upon the interest of the fund. For this we 

 must make automatic and habitual, as early 

 as possible, as many useful actions as we 

 can, and guard against the growing into 

 ways that are likely to be disadvantageous 

 to us, as we should guard against the 

 plague. The more of the details of our daily 

 life we can hand over to the effortless cus- 

 tody of automatism, the more our higher 

 powers of mind will be set free for their own 

 proper work. There is no more miserable 

 human being than one in whom nothing is 



. habitual but indecision, and for whom . . . 

 the drinking of every cup. the time of rising 

 and going to bed every day, and the begin- 



ning of every bit of work, are subjects of ex- 

 press volitional deliberation. Full half the 

 time of such a man goes to the deciding, or 

 regretting, of matters which ought to be so 

 ingrained in him as practically not to exist 

 for his consciousness at all. If there be such 

 daily duties not yet ingrained in any one of 

 my readers, let him begin this very hour to 

 set the matter right. JAMES Psychology, 

 vol. i, ch. 4, p. 122. (H. H. & Co., 1899.) 



746. DECLINE OF CIVILIZATION 



Better Implements Converted into Poorer to 

 Suit a Lower Grade of Workers. There is 

 an instructive lesson to be learned from a re- 

 mark made by an Englishman at Singapore, 

 who noticed with surprise two curious 

 trades flourishing there. One was to buy 

 old English-built ships, cut them down, and 

 rig them as junks; the other was to buy 

 English percussion-muskets and turn them 

 into old-fashioned flintlocks. At first sight 

 this looks like mere stupidity, but on con- 

 sideration it is seen to be reasonable enough. 

 It was so difficult to get Eastern sailors to 

 work ships of European rig that it an- 

 swered better to provide them with the 

 clumsier craft they were used to ; and as for 

 the guns, the hunters far away in the hot, 

 damp forests were better off with gun-flints 

 than if they had to carry and keep dry a 

 stock of caps. In both cases, what they 

 wanted was not the highest product of civili- 

 zation, but something suited to the situation 

 and easiest to be had. Now the same rule 

 applies both to taking in new civilization 

 and keeping up old. When the life of a peo- 

 ple is altered by emigration into a new 

 country, or by war and distress at kme, or 

 mixture with a lower race, the culture of 

 their forefathers may be no longer needed or 

 possible, and so dwindles away. TYLOR 

 Anthropology, ch. 1-, p. 19. (A., 1899.) 



747. DECOMPOSITION, BACTERIA 



OF Cycle of Building Up and Breaking Down. 

 It is clear that there is in all animal life 

 a double process continually going on ; there 

 is a building up (anabolism, assimilation), 

 and there is a breaking down Ckatabolism, 

 dissimilation). These processes will not 

 balance each other throughout the whole 

 period of animal life. We have, as possi- 

 bilities, elaboration, balance, degeneration; 

 and the products of animal life will differ in 

 degree and in substance according to which 

 period is in the predominance. These prod- 

 ucts we may subdivide simply into excre- 

 tions during life and final materials of dis- 

 solution after death, both of which may be 

 used more or less immediately by other 

 forms of animal or vegetable life, or medi- 

 ately after having passed to the soil. . . . 

 The carbonic acid, water, and other simple 

 substances like them will return to Nature 

 and be of immediate use to vegetable life. 

 But otherwise the cycle cannot be completed, 

 for the more complex bodies are of no serv- 

 ice as such to plants or animals. In order 

 that this complex material should be of 



