COMMON OBJECTS WORTH EXAMINING. 277 



terest to the beginner, and, indeed, to any one. They 

 are all very accessible in the writer's locality ; it is 

 hoped that they are equally accessible to the reader. 

 The list is intended only as a start, or a hint as to what 

 may be examined, and be interesting yet common and 

 abundant. The beginner will soon cease to be a begin- 

 ner. He will before long become so interested in some 

 special class of nature's handiwork that he will leave 

 all the others and devote himself to that one. No sin- 

 gle student can expect or hope to cultivate all depart- 

 ments of microscopical science. The field is too vast 

 and life is too short. Most heartily would I recom- 

 mend the beginner in the use of the microscope to 

 spend several years, if necessary, in taking short excur- 

 sions into as many different microscopical departments 

 as possible, and to then intelligently make a selection of 

 some one scientific field, of which there are many, and 

 make its cultivation the work and the recreation of his 

 leisure hours. The work will soon become recreation, 

 and the recreation will soon result in increased knowl- 

 edge not only to the student-worker but to the scientific 

 world at large. There can be no better way of employ- 

 ing one's leisure hours than by scientific work or even 

 by scientific play. The illustrious Leidy, one of the 

 greatest of living naturalists and investigators, says in 

 his monograph on the fresh-water Khizopods of North 

 America, "The study of natural history in the leisure 

 of my life, since I was fourteen years of age, has been 

 to me a constant source of happiness, and my experience 



