659 



SCIENTIFIC SIDE-LIGHTS 



Strength 

 Struggle 



3257. STRUCTURE OF THE HEAV- 

 ENS, COMPLICATED Nebula of Many 

 Types The Magellanic Clouds Contrasted 

 with Starless Spaces, the " Coal Sacks." 

 Mysterious objects [the nebulae], voices of 

 the past, prophecies of the future, these soft 

 and pale gleams open to the mind new per- 

 spectives in infinitude; the first telescopic 

 observers of the sky, who treasured the mem- 

 ory of the empyrean, described them as 

 openings through the celestial vault, per- 

 mitting our gaze to penetrate to the light 

 of Paradise. The types on which we have 

 fixed our attention give still but an in- 

 complete idea. We should add the lenticu- 

 lar and elliptical nebulas; the perforated 

 nebulae; nebulous rays; the great cloud of 

 Magellan, at 20 from the south pole, which 

 contains 291 nebulae, 46 stellar clusters, and 

 582 stars, and covers 42 square degrees of 

 the sky; the smaller cloud, which occupies 

 10 square degrees, contains 200 stars, 37 

 nebulae, and 7 clusters; and not far from 

 that the " coal sacks," regions entirely void 

 of stars, yawning openings in the sidereal 

 universe, as if a waterspout had devastated 

 them; and, again, the faintest nebulae lost 

 in the depths of the sky, whose light would 

 take, according to the Herschelian estimates, 

 two millions of years to reach us! FLAM- 

 MARIOX Popular Astronomy, bk. vi, ch. 10, 

 p. 665. (A.) 



3258. STRUGGLE AND CONFLICT 

 BEHIND THE BEAUTY AND ORDER OF 

 NATURE To most persons Nature ap- 

 pears calm, orderly, and peaceful. They see 

 the birds singing in the trees, the insects 

 hovering over the flowers, the squirrel climb- 

 ing among the tree-tops, and all living things 

 in the possession of health and vigor and 

 in the enjoyment of a sunny existence. But 

 they do not see and hardly ever think of 

 the means by which this beauty and har- 

 mony and enjoyment are brought about. 

 They do not see the constant and daily search 

 after food, the failure to obtain which means 

 weakness or death; the constant effort to 

 escape enemies; the ever-recurring strug- 

 gle against the forces of Nature. This daily 

 and hourly struggle, the incessant warfare, 

 is nevertheless the very means by which 

 much of the beauty and harmony and enjoy- 

 ment in Nature are produced, and also affords 

 one of the most important elements in bring- 

 ing about the origin of species. WALLACE 

 Darwinism, ch. 2, p. 10. (Hum.) 



3259. 



Among All Plants 



The More Vigorous Choke the Weaker 

 (Matt, sciii, 7). "All the plants of a given 

 country," says De Candolle, in his usual 

 spirited style, " are at war one with another. 

 The first which establish themselves by 

 chance in a particular spot tend, by the 

 mere occupancy of space, to exclude other 

 species the greater choke the smaller; the 

 longest livers replace those which last for 

 a shorter period; the more prolific gradually 



make themselves masters of the ground 

 which species multiplying more slowly would 

 otherwise fill." In this continual strife it 

 is not always the resources of the plant 

 itself which enable it to maintain or extend 

 its ground. Its success depends, in a great 

 measure, on the number of its foes or allies 

 among the animals and plants inhabiting 

 the same region. Thus, for example, an herb 

 which loves the shade may multiply, if some 

 tree with spreading boughs and dense foliage 

 flourish in the neighborhood. Another, which, 

 if unassisted, would be overpowered by the 

 rank growth of some hardy competitor, is 

 secure because its leaves are unpalatable to 

 cattle, which, on the other hand, annually 

 crop down its antagonist, and rarely suffer 

 it to ripen its seed. LYELL Principles of 

 Geology, bk. iii, ch. 40, "p. 670. (A., 1854.) 



326O. STRUGGLE FOR LIFE, THE 



Among Ants. Almost everything is in- 

 vaded by the structures of ants. Where 

 there are no real nests there are under- 

 ground passages and galleries, open roads, 

 covered ways; or, at least, the inhabitants 

 of neighboring nests are out scouting, con- 

 tending with one another for the possession 

 of plants containing plant-lice and cochineal 

 kermes, for the possession of the trees, the 

 flowers, and the insect plunder. 

 Ants certainly, no less than men, fancy 

 themselves the lords of creation; for, owing 

 to their social organization, their numbers, 

 and their courage, they have few foes to 

 fear. Their most formidable foes are other 

 ants, just as men are the worst foes of men. 

 In the tropical world the struggle for exist- 

 ence is much fiercer than with us, and the 

 ants, with their immense number of species, 

 play a much more important part. Their 

 nest - structures are correspondingly more 

 varied there, displaying far more singular 

 and complicated adaptations as the result 

 of the struggle for life. FOREL Ants' Nests 

 (Report of Smithsonian Institution, 1894, 

 p. 503). 



3261. 



Among Bacteria. 



There is in these media [water and sew- 

 age] in Nature a keen struggle for the 

 survival of the fittest bacteria for each 

 special medium. In a carcass it is the 

 same. If saprophytic bacteria [bacteria of 

 decomposition] are present with pathogenic 

 [disease-producing], there is a struggle for 

 the survival of the latter. Now whilst this 

 is in part due to a competition owing to a 

 limited food supply and an unlimited popu- 

 lation, as occurs in other spheres, it is also 

 due in part to the inimical influence of the 

 chemical products of the one species upon 

 the life of the bacteria of the other species. 

 Moreover, in one culture medium, as Cast 

 has pointed out, two species will often not 

 grow. When Pasteur found that exposure 

 to air attenuated his cultures, he pointed 

 out that it was not the air per se that hin- 

 dered his growth, but it was the introduc- 



