294 



NATURE 



[December 13, 1917 



tina, where he found these birds in considerable num- 

 bers foisting their eggs upon numerous species of small 

 ■birds, especially finches. But for choice they seem 

 "always to prefer the mud nests of the oven-bird (Fur- 

 narius). These seem to have an irresistible and fatal 

 attraction for cow-birds, since all the eggs deposited 

 therein appear invariably to be destroyed by the deser- 

 tion of the intended dupes, which, whenever they dis- 

 cover the trick that has been played upon them, cover 

 up the eggs with a layer of nesting material, refusing 

 to incubate. In some nests layer after layer of eggs 

 were thus found, but no young were ever met with. 

 The numbers of eggs found in such nests ranged from 

 six to as many as thirty-seven ! While this stupidity 

 reduces the numbers of the parasites, it at the same 

 time reduces the number of oven-birds, which, in the 

 areas explored by Mr. Miller, failed to produce off- 

 spring. Judging from the coloration of the eggs, Mr. 

 Miller estimated that in some cases as many as thirteen 

 birds may use the same nest. The eggs of a third 

 species (M. rujoaxillaris) were also occasionally found 

 in these nests. 



That the pin-tailed widow-bird has developed the 

 parasitic habits of the cuckoo seems to be established, 

 judging from the evidence of Mr. Austin Roberts in 

 the Annals of the Transvaal Museum, vol. v., part 4. 

 Mr. Roberts tells us that he has known this bird to 

 deposit its eggs in the nests of no fewer than four 

 different species of waxbill, as well as in those of its 

 relative, the red-collared widow-bird. It frequently de- 

 posits more than tone egg in the nest of its host, and 

 sometimes it replaces the whole clutch. But in no ease 

 does the foundling appear to dislodge the rightful occu- 

 pants of the nest, vi^hich is the invariable custom of the 

 cuckoo. Mr. Roberts believes that two other finches 

 are similarly parasitic. These are Rendall's seed-eater 

 (Anomalospiza imberhis) and the red-billed weaver 

 (Ouelea sanguinirostris). But we venture to think that 

 a mistake has been made, at least in the case of the 

 last-named species, which even in capitivity shows no 

 degeneration in the matter of its parental instincts. 



SCIENCE AND ITS FUNCTIONS J 

 C INCE the earliest times, man, like his poor relation 

 •-^ . the monkey, has always been of a curious disposi- 

 tion, and has wanted 10 know the why and wherefore, 

 as well as the mechanism, of all the phenomena that 

 he sees about him. No doubt much early science, 

 especially in the fields of astronomy and alchemy, 

 was practised as a eult, with the view of impressing 

 and mystifying the common people, but at the back 

 of it all there can be little question that the great force 

 that impelled inquiry into Nature, both in ancient times 

 and in the modern world, was curiosity, which in itself 

 is probably of all human emotions the one that has 

 been most conducive both to intellectual and to material 

 progress. 



With the appearance in history of that wonderful 

 people the Greeks, we come for the first time in per- 

 sonal contact with the scientific thoughts and the 

 scientific theories of individual philosophers. Prior to 

 that period there must have been scientific thinkers, 

 but we have no distinct record of what their scien- 

 tific ideas were. All that remains are portions of some 

 of their material constructions, and some accounts of 

 others that time and decay have destroyed. Thales of 

 Miletus, one of the seven wise men of the Grecian 

 golden age, though he lived some 600 years before our 

 area, is no mere name. He was the founder Q,f the 

 physical school of Greek philosophy, who first began 

 to consider the nature of things, and was the first 



1 From an address delivered before the Koval Society of Arts on 

 November 21 by A. A. Campbell Swinton, F.R.S., Chairman of the 

 Council. 



NO. 25 1 1, VOL. 100] 



to observe electrical action. To Democritus, a Greek 

 of the fourth century B.C., we owe the earliest ideas 

 about matter, while to Hippocrates, another early 

 Greek, are due the beginnings of medicine and biology. 

 To him is ascribed the immortal and pregnant phrase 

 that while " Life is short, Art is long. Opportunity 

 fleeting. Experiment uncertain, Judgment difficult"-^ 

 an aphorism in which is summed up for all time the 

 difficulties with which the scientific investigator has 

 to contend. And so we pass on to that most famous 

 of classical philosophers, Aristotle, whose writings 

 have done more than those of any other man to influ- 

 ence the progress of science, and whose authority was 

 so great that it bound the scientific world in iron 

 fetters for centuries. In the great library and museum 

 which was founded in the third century B.C. by 

 Ptolemy at Alexandria, then the intellectual and com- 

 mercial capital of the Grecian world, we find the 

 apotheosis of Greek scientific activity. Here were pre- 

 served all the scientific writings and records that a 

 world-wide search had enabled the founder to collect. 

 Here were taught the philosophy of Aristotle and the 

 geometry of Euclid. Here Claudius Ptolemy experi- 

 mented in optics, and wrote his great work on the 

 construction of the heavens. Here Eratosthenes 

 measured the earth. Here Ctesibius invented the fire- 

 engine, and Hero the first steam-engine, which, it is 

 interesting to note, was a simple form of steam tur- 

 bine. Here worked Archimedes, the most famous 

 mathematician and physicist of the ancient world, who 

 laid the foundation of hydrostatics, elucidated the 

 theory of the lever, and invented the burning-glass 

 and the screw-pump which still bears his name. As 

 a man of science the world produced no equal to him 

 for nearly two thousand years. But the days of the 

 great library were numbered, and within those marble 

 halls the drip of the water-clocks of Apollonius were 

 counting drop by drop, and second by second, the ap- 

 proach of the catastrophe. During the siege of Alex- 

 andria by Julius Caesar the library and all its con- 

 tents were burnt — a fitting funeral pyre to the glory 

 that was Greece. 



The Romans made r^o contributions to pure science 

 at all to be compared with those of the Greeks. They 

 were a practical rather than a speculative people, and 

 were great builders, engineers, and road-makers. Size, 

 solidity, and quantity rather than novelty were the 

 outstanding features of their scientific work. Thev 

 were not like the Greeks, ever seeking after some 

 new thing. 



When Rome fell into decay, and the gloom of the 

 Dark Ages settled down upon Europe, there was for 

 a time an almost complete halt in the progress of 

 science. True, some vestige of learning still struggled 

 to maintain itself in what was left of the Alexandrian 

 library, but this was finally extinguished by the latter's 

 second destruction by order of the Arabian Khalif, 

 Omar. After this it is somewhat surprising that the 

 next revival in scientific investigation took place 

 amongst the Arabians themselves, now become a 

 highly^ cultured people. To this revival we owe the 

 invention of algebra, the beginning of systematic chem- 

 istry, and much new work in astronomy, medicine, 

 mechanics, and metallurgy. One of the most famous 

 of the Arabian experimental philosophers was Alhazan, 

 who lived shortly before the Norman Conquest of 

 England. 



When there began in Europe that great revival of 

 learning known as the Renaissance, it was the print- 

 ing press that became its principal coadjutor, and 

 caused things to move at a rate much faster and on 

 a scale much larger than ever before. It was with 

 fundamental concepts that the new learning had first 

 of all to contend, particularly with the geocentric 

 theory of the universe, which gave to the earth and 



