Aquatic Life 19 



Agassiz, an inspiring teacher, and founder of the first 

 of our biological field stations; Dr. Joseph Leidy, an 

 excellent zoologist of Philadelphia, and Alfred C. Stokes 

 of New Jersey, whose Aqtiatic Microscopy is still a use- 

 ful handbook for beginners. 



Our knowledge of aquatic life has been long accumu- 

 lating. Those who have contributed have been of very 

 diverse training and equipment and have employed 

 very different methods. Fishermen and whalers ; col- 

 lectors and naturalists; zoologists and botanists, with 

 specialists in many groups; water analysts and sani- 

 tarians; navigators and surveyors; planktologists and 

 bacteriologists, and biologists of many names and sorts 

 and degrees; all have had a share. For the water has 

 held something of interest for everyone. 



Fishing is one of the most ancient of human occupa- 

 tions; and doubtless the beginning of this science was 

 made by simple fisher-folk. Not all fishing is, or ever 

 has been, the catching of fish. The observant fisherman 

 has ever wished to know more of the ways of nature, and 

 science takes its origin in the fulfillment of this desire. 



The largest and the smallest of organisms live in the 

 water, and no one was ever equipped, or will ever be 

 equipped to study any considerable part of them. 

 Practical difficulties stand in the way. One may not 

 catch whales and water-fleas with the same tackle, nor 

 weigh them upon the same balance. Consider the dif- 

 ference in equipment, methods, area covered and num- 

 bers caught in a few typical kinds of aquatic collecting: 



(i). Whaling involves the cooperative efforts of 

 many men possessed of a specially equipped vessel. A 

 single specimen is a good catch and leagues of ocean 

 may have to be traversed in making it. 



(2). Fishing may be done by one person alone, 

 equipped with a hook and line. An acre of water affords 

 area enough and ten fishes may be called a good catch. 



