vi INTRODUCTION 



the voice of Nature, and had gone forth into the fields and lanes, 

 and along the seashore to pursue their studies, were laughed to 

 scorn, or looked upon as revolutionary, if not dangerous heretics. 

 But these early pioneers laboured not in vain ; interest was 

 aroused, and gradually the old pedantic, narrow outlook widened, 

 until the publication of Darwin's " Origin of Species " established 

 and vindicated for all time the importance of biology, the study 

 of the organism in relation to environment. 



Since that time the history of the study of animal life has 

 been one of rapid and steady progress, fraught with far-reaching 

 and important results. Take, for example, the rapid progress 

 within the last fifteen or twenty years of our knowledge of the 

 protozoa, and of the important part which we now know many 

 of these unicellular organisms to play as the primary cause of many 

 deadly tropical diseases, such as malaria, yellow fever, and sleep- 

 ing sickness. Biological investigation has revealed not only the 

 organisms that produce the malignant diseases, but the transmitting 

 agents that carry them from man to man discoveries of far- 

 reaching economic importance, making for the commercial advance 

 and prosperity of tropical lands, where formerly fevers rendered 

 life almost insupportable. The engineer will proudly acclaim the 

 completion of the Panama Canal as one of the wonders of mecha- 

 nical science, but its successful accomplishment has only been 

 rendered possible by biological research, through which the know- 

 ledge of how to combat the ravages of malaria and yellow fever 

 among the vast army of workers employed upon the undertaking 

 has been acquired. v 



The study of life in the sea marine biology has made con- 

 siderable progress of late years, and is becoming of ever greater 

 importance, not only from the purely scientific point of view, 

 but in connection with fishery questions and the " harvest of 

 the sea." Thanks to the energy of Sir E. Ray Lankester, the 

 Marine Biological Association of the United Kingdom was founded 

 in 1884, and since its inception has carried out investigations of 

 far-reaching scientific and economic importance, adding to our 



