NovEMnER, 1928 



EVOLUTION 



Page Eleven 



THE AMATEUR SCIENTIST 



A Monthly Feature conducted by Allan Strong Broms 



BIRDS' FEET 



The delightful thing about science Is 

 that it explains plainly the mysterious 

 facts we see about us. It teaches the eye 

 to see facts and read solutions. Take 

 birds' feet, for example. Offhand, the 

 amateur %vould think of them as more or 

 less all alike, but really look at them once 

 with the eyes of science and you will know 

 them ever after as of distinct types, each 

 telling a story of the life of the bird. For 

 each bird has feet that fit its way of liv- 

 ing, and by their feet you shall know them. 



In the picture are seven kinds of feet, 

 each used in a characteristic way. (1) The 

 shag or cormorant has a webbed foot for 

 swimming, as it lives the life of a fisher- 

 man. (2) Quite different is the foot of 

 the tree dwelling crow, the toes being 

 long and curved for grasping the branch 

 on which it perches, one of the toes being 

 moved back to encircle the branch from 

 the opposite side. (3) The Ptarmigan 

 lives on the treeless barrens of the arctic 

 regions, and has a foot broad and padded 

 for running and well wrapped in a warm 

 stocking of feathers. (4) The wild jungle 

 fowl needs no stocking to keep warm, but 

 it does walk and stalk about, its flatly 

 spreading toes helping it keep its balance. 

 The fourth toe is lifted a bit and sharp- 

 ened into a spur, a handy weapon in the 

 jungle battles over some fair hen. With 

 the other toes it scratches a living for the 

 family. (5) The coot or mud-hen just 

 lives in the water, its lobate-webbed feet 

 making good oars for fast swimming and 

 diving. (6) Jacana leads a strange life, 

 walking on floating leaves, its weight well 

 distributed by its long, wide-spreading 

 toes. (7) The strong, curved talons of the 

 sea-eagle tell the whole story of its preda- 

 cious habits, its swift attack on its fish or 

 other victim, claws striking hard to kill 

 and digging deep to hold and carry off 

 the flesh food it brings home to Its family. 



Each has its own way of life and its 

 body parts fitted to that life. It has found 



a place In the affairs of the world and by 

 varying to lit that place it has survived 

 in the struggle for existence. As each 

 found a somewhat different place (en- 

 vironment), there result unlimited varie- 

 ties, and species and broader groups, each 

 adapted in structure and habits to the con- 

 ditions into which it grew. 



ICE SIGNS 



These late fall days of barren hills are 

 good for amateur geologising. The air is 

 bracing, walking is fine and most of you 

 live within the glaciated area shown on 

 the map, within which there is no end of 

 signs of the great, mile-thick Ice sheet that 

 covered four million square miles of nor- 

 thern North America within quite recent 

 times. Only one small section in Illinois, 

 Iowa, Minnesota and Wisconsin was not 

 touched by the ice. Europe also had its 

 ice sheet centered in Scandinavia and 

 spreading out over Germany and the Brit- 

 ish Isles. Perhaps there was but one great 

 ice sheet over the two continents which 

 were then closer together and have since 

 drifted apart. Certainly, however, the 

 ice-cap now covering Greenland is the 

 remnant of the continental ice-sheet that 

 spread from several Canadian centers. 



The signs are on the surface and easy 

 to read ; clay mixed with boulders and 

 pebbles and sand, heaped into small, 

 rounded hills, just as it was dumped by 

 the melting ice, with little or no water 

 sorting such as we find In water-laid 

 strata; chains of irregular, shallo%v lakes 

 connected by short streams that wander 

 aimlessly over the topographic maze. Some 

 of the boulders are strangely unlike the 

 rocks native to the neighborhood, and very 

 like other rock beds tens, even hundreds, 

 of miles northward, from which they were 

 quarried and carried by the moving mass. 

 The bed rock Itself may be planed, or 

 grooved, or scratched by the heel of the 

 noving ice sheet, a heel full of hob-nail 

 rocks frozen to the sliding glacier bottom. 



^^Scg^ 



Ice-shcct centers; I, Cordilleran; II Keewatin; 

 III, Labradoreaii; IV, Newfoundland. 



LOOKING BEFORE AND AFTER 



By Joseph McCabe 



Someone once defined man as the animal 

 who looks before and after. It is not a 

 bad definition, for all the claims that a 

 bird or wasp, for instance, looks forward, 

 when It builds a nest to its coming pro- 

 geny, are now disallowed. It requires the 

 higher type of mind which distinguishes 

 man to forecast the future and build up 

 a constructive and entire picture of 

 phases of the earth which have passed 

 away. The chief defect of the definition 

 is that it leaves so few of us really human. 

 Most of us live in the task or the enter- 

 tainment of the hour. 



At the most we know only of the past 

 that our political party won a great victory 

 in the year so-and-so, and of the future 

 only that the football or baseball season 

 opens on such a date. It is a slight im- 

 provement on the psychology of the sheep, 

 but it argues some defect in the costly 

 scheme of education which has spent seven 

 or eight laborious years on us. 



But if we take the human mind in its 

 higher representatives, the men of science, 

 we seem compelled to say that in the last • 

 century or so it has made a prodigious rise 

 in the scale of intelligence. Young men 

 sometimes severely rebuke me after my 

 evolutionary lectures and point out that 

 "there has been no improvement in the 

 human mind for the last twenty thousand 

 years." They picked this up in the 

 works of certain American men of science, 

 not one of whom is an anatomist, and each 

 of whom, has a theological bee in his 

 bonnet. You know what their idea is. 

 Cro-Magnon man, of the late Cave Period, 

 has so large a brain — I won't repeat the 

 dreary catechism. Whatever clues to the 

 texture of the brain — the size alone tells 

 nothing, for only a few ounces of the brain 

 are Involved in intellectual operations — 

 an ancient skull may give, it certainly can- 

 not prove the precise power of thinking 

 of the dead man. 



The real meaning of this eccentric 

 opinion is "spook-stuff." These professors 

 are not really concerned about the com- 

 parison between the brain of Cave Man 

 and ours. They are comparing it with the 

 brain of his predecessor ; and they are 

 simply trying, by a desperate twist of the 

 scientific evidence, to prove that the mind 

 made so miraculous an advance in the 

 last phase of the Old Stone Age that evo- 

 lution cannot explain it, and we must 

 admit the appearance on the scene at last 

 of a real spiritual soul. 



Probably the highest achievement of the 

 modern mind in the way of looking before 

 and after is a certain vast mathematical 

 conception of the universe. 



I will tell you in my next article why this 

 mathematical estimate of past and future 

 time seems to me so full of important 

 human interest that I would spend months, 

 if necessary, to see that every child was 

 thoroughly and intimately familiar with 

 the outline of it before it left school. 



