THE BIOLOGICAL LITERATURE 25 



A new field can best be approached by first getting a broad general 

 picture. One simple means of accomplishing this objective is to learn it 

 first-hand from someone familiar with the field. If this is impossible, a 

 recent textbook provides a point of beginning. The textbook may be a 

 dead-end source, but most now include at least a few references to more 

 advanced literature. Several encyclopedias also are excellent starting 

 points. Encyclopaedia Britannica and Encyclopedia Americana give quite 

 detailed coverage of many biological topics, and many of the articles 

 provide references. The McGraw-Hill Encyclopedia of Science is gen- 

 erally excellent. Several one-volume specialized encyclopedias have ap- 

 peared recendy, such as the Encyclopedia of Microscopy and the Encylo- 

 pedia of Spectroscopy. 



Eventually, references obtained from textbooks and from encyclo- 

 pedias take one to the review articles, and references given in these lead 

 quite directly to the original technical reports. By this time the reader 

 will have a good idea of what is known in the specific field. Other papers 

 can be found in the abstract journals. Chemical Abstracts, for example, 

 publishes annually a subject index, an author index, and an index of 

 chemical formulae. At ten-year intervals, they produce decennial in- 

 dexes. If you wished to find all the papers on a subject covered by this 

 service, you could trace the annual indexes back to the most recent 

 ten-year index. The abstracts you find will tell you whether it is worth 

 seeking the original paper. 



Somewhere you must stop your search through literature, lest it go 

 on forever and keep you out of the laboratory. Just when to consider 

 your knowledge of the field adequate is a matter of personal judgment. 

 I think we learn primarily by experience. 



Other sources of information 



Handbooks of various sorts are just as indispensable as are diction- 

 aries. The physical and chemical handbooks give tabulated data on 

 almost any imaginable subject. The Handbook of Biological Data in- 

 cludes specifically biological information. The first edition is somewhat 

 difficult to use until you become famiHar with it, but the chances are 

 good that if a fact about an organism is known it has been included. 



A source of ideas that is sometimes neglected is the collection of 

 materials provided by the concerns that make or sell supphes and equip- 

 ment. The catalogue of a glassware manufacturer, for example, might 



