34 Mac LEOD, The Place of Science in History. 



discoveries. Thus prepared, he commenced the study of 

 microbes, and to this study devoted more than thirty 

 years of his life. 



Whatever be the example we choose, the lesson to be 

 drawn from it is always the same. Each definite advance 

 has been realised little by little, by a series of successive 

 steps, and by the indefatigable work of men prepared by 

 serious studies. 



The history of the evolution of the natural sciences 

 contains yet other lessons. The discoveries are innumer- 

 able which, when they were made, were only a simple 

 statement of new truths, and which later took an immense 

 importance. It is in this spirit that numbers of entomo- 

 logists have for centuries patiently collected and described 

 innumerable insects ; have studied the ways of these little 

 animals, their methods of feeding and their metamorphoses. 

 Led by the desire to discover truth and to gather together 

 collections of these minute forms of life, which are often 

 of a remarkable beauty, they have accomplished a work 

 which might well seem futile. But to-day we recognise 

 more and more the immense services which entomologists 

 have rendered us, and continue to render ; it is sufficient 

 to remember the application of entomology to agriculture, 

 and to medicine, especially to the study of certain tropical 

 diseases. And the cryptogamists who have studied and 

 collected a crowd of little plants, completely insignificant 

 in appearance, — have they not created, little by little, a 

 new science, which endeavours to combat the parasitic 

 diseases of cultivated plants, and which bears to-day the 

 most splendid fruits ? 



A characteristic trait of the conquests accomplished 

 by the great impulse which creates riches and alleviates 

 evils by means of truth, is the complete disproportion 

 existing between the price of the conquests and their 



