BIOLOGY IN ITS WIDER ASPECTS 1207 



vividly for a moment of some modem achievements. Science has 

 brought the stars to within its measurement and even weighed 

 some of them in its balance; it has knocked to pieces what so long 

 seemed indivisible atoms ; it has mastered some of the many octaves 

 on the long gamut of electro-magnetic radiations, using those at 

 one end for broadcasting, and those at the other end for radio- 

 therapy. Utilising Becquerel's great discovery of radio-activity, 

 science detects the bullet deep buried in the bone or even brain, 

 and sees the pearl hidden in the unopened oyster; it is beginning 

 to see the invisible, and even from a great distance. By means of 

 powerful electric discharges, man is now tapping the inexhaustible 

 supply of nitrogen in the atmosphere, and using it for the synthesis 

 of fertilisers — thus multiplying his loaves out of the thin air. 



And if it be said that these illustrations of scientific achievement 

 are in the physical world, whereas our troubles are in the world of 

 life, we have only to recall some of the many victories that are to 

 the credit of modem medicine with Biology at its back. The first 

 services of bacteriology and its "germ-theory" of disease to surgery, 

 and to medicine also — ^witness yeUow fever practically abolished 

 and Malaria coming under control — are now of common knowledge. 

 So a few illustrations will here suffice. 



One of the heaviest mundane clouds that has of recent years 

 seemed spreading on the human race in warm countries is 

 Ankylostomiasis — a wasting disease traced to a contemptible little 

 threadworm that finds entrance into man through the skin of his 

 bare feet. But this "hookworm" is now being practically con- 

 quered; it is easily expelled from the human body, and reinfection 

 can be prevented — ^wherever man is willing — ^by simple sanitary 

 precautions. Thus the clouds of "tropical depression" — implying 

 debility, despair, and dreary premature death — are being lifted. 

 Already in some places the incidence of hookworm disease has 

 been reduced from about twenty-five per cent, to about three. What 

 can Science not do ? 



Of the 30,000 or so children bom every year in Cairo, 10,000 are 

 said to be attacked by the painful and weakening disease of Bil- 

 harziasis, due to a fluke-worm, whose minute larva enters the body 

 from the water in which the children paddle. During the Great 

 War, when this parasitic worm (Schistosomum) was very trouble- 

 some to our soldiers in Egypt, Major Leiper unravelled its compli- 

 cated life-history, and found its young stages in water-snails. More 

 than that, he showed that if the water in which the minute free- 

 swimming larvae swarm is left still in cisterns and the like, the larvae 

 die off, so that the water is no longer infective. Bilharzia thus is 

 theoretically conquered. 



A cretinoid child, arrested in the development of its body and 

 •mind, is one of the saddest of sights. Its thyroid gland is not fvmction- 



