407 



SCIENTIFIC SIDE-LIGHTS 



Lojric 

 Loss 



with its subsidiary losses, contributes to 

 reduce this essential element of all life; and 

 if there were no method of bringing it back 

 again to the soil it would seem that plant- 

 life, and therefore animal-life, would speed- 

 ily terminate. 



It is at this juncture, and to perform this 

 vital function, that the nitrogen-fixing [ni- 

 trifying] bacteria play their wonderful 

 part: they bring back the free nitrogen 

 and fix it in the soil. NEWMAN Bacteria, 

 ch. 5, p. 160. (G. P. P., 1899.) 



1989. LOSS NOT EASILY REPAIRED 



Removal of Earth's Vegetable Covering 

 Deserts Hay Remain Desolate for Ages. 

 The origin of this absence of plants over 

 large tracts of land, in regions characterized 

 on every side by the most exuberant vegeta- 

 tion, is a geological phenomenon which has 

 hitherto received but little attention; it un- 

 doubtedly arises from former revolutions 

 of Nature, such as inundations, or from vol- 

 canic convulsions of the earth's surface. 

 When once a region loses its vegetable cov- 

 ering, if the sand is loose and devoid of 

 springs, and if vertically ascending currents 

 of heated air prevent the precipitation of 

 vapor, thousands of years may elapse be- 

 fore organic life can penetrate from the 

 green shores to the interior of the dreary 

 waste. HUMBOLDT Views of Nature, p. 216. 

 (Bell, 1896.) 



1990. LOSS OF PRIMITIVE SIM- 

 PLICITY Civilisation Not an Unmixed Gain 

 Womanly Arts Not Improved. There 

 ought to be no doubt that in every case 

 where the savage was fortunate enough to 

 obtain the knife, his carving and whittling 

 were better done. There is a marvelous dif- 

 ference between carving, on the one hand, 

 man's work chiefly, and basketry or pottery, 

 on the other, conservative woman's work. 

 In no tribes were the two last-named arts 

 bettered by contact with the higher race. 

 The work was done with the hands almost 

 wholly. The tools were of the simplest 

 character. The harsh iron awl was not to 

 good as the smooth -pointed bone awl, of 

 which hundreds have been found, and the 

 pride in personal endeavor departed with 

 the quenching of the tribal spirit. The pot- 

 ter's wheel, such as it was three centuries 

 ago, was only a barrier to the unmechanical 

 sex. Therefore those who constantly assert 

 that prejudice made it impossible for the 

 savage to better himself in the adoption of 

 the white man's devices catch only half a 

 truth. MASON The Man's Knife among the 

 North American Indians (Report of the 

 V. 8. National Museum for 1897, p. 727). 



1991. LOSS THROUGH DISUSE 



Atrophy of Optic Nerve The Mole Has True 

 Eyes. This animal [the mole], whose pe- 

 culiar habits are known to every one, has 

 true eyes, from which none of the essential 

 parts of the eyes of the Vertebrata are 

 absent, altho these parts are all of the 



simplest, almost of embryonic structure. 

 The whole eye is very small, deeply embed- 

 ded in muscles, and quite covered by the 

 skin, so that it is quite invisible externally. 

 The lens consists of a very small number 

 of minute and little altered embryonic cells; 

 the retina, in the same way, is much simpler 

 than in the eyes of other Vertebrata. True 

 degeneration, then, such as makes the eye 

 incapable of seeing, has not taken place; 

 nevertheless the eye of the mole is reduced 

 to almost total inefficiency even when by 

 chance it has an opportunity for using it. 

 This almost total blindness in the mole is 

 the result solely of complete degeneration 

 of the optic nerve, so that the images which 

 are probably formed in the eye itself can 

 never be transmitted to the animal's con- 

 sciousness. Occasionally, however, the mole 

 even can see a little, for it has been found 

 that both optic nerves are not always de- 

 generate in the same individual, so that one 

 eye may remain in communication with the 

 brain while the other has no connection with 

 it. In the embryo of the mole, however, and 

 without exception, both eyes are originally 

 connected with the brain by well-developed 

 optic nerves, and so theoretically efficient. 

 This may indeed be regarded as a perfectly 

 conclusive proof that the blind mole is de- 

 scended from progenitors that could see; it 

 would seem, too, to prove that the blindness 

 of the fully grown animal is the result, not 

 of inheritance, but of the directly injurious 

 effects of darkness on the optic nerve in 

 each individual. SEMPER Animal Life, ch. 

 3, p. 79. (A., 1881.) 



1992. 



Atrophy of Wings 



of Great Auk. One of the characteristic 

 water-birds of our North Atlantic coasts is 

 the razor-billed auk. . . . During the 

 winter it migrates southward as far as Long 

 Island. Flight is therefore a necessary fac- 

 ulty, and we find the bird with well-de- 

 veloped wings, which it uses effectively. 

 We can, however, imagine conditions un- 

 der which it would not be necessary for the 

 razor-bill to fly. It might become a per- 

 manent resident of isolated islands, laying 

 its egg on accessible beaches. Already an 

 expert diver, obtaining its food in the wa- 

 ter, it would not be obliged to rise into 

 the air, and, as a result of disuse, the wings 

 would finally become too small to support 

 it in aerial flight, tho fully answering the 

 purpose of oars. Apparently this is what 

 has happened in the case of the razor-billed 

 auk's relative, the flightless, extinct great 

 auk. The razor-bill is sixteen inches long 

 and its wing measures eight inches, while 

 the great auk, with a length of thirty inches, 

 has a wing only five and three- fourths inches 

 in length. Aside from this difference in 

 measurements these birds closely resemble 

 each other. So far as we are familiar with 

 the great auk's habits, they agreed with 

 those of the hypothetical case I have, just 

 mentioned, and we are warranted, I think, 



