WHY A BIOLOGY LABORATORY? 



A foreword to the Student 



Science is an attempt to understand reality. 

 The questions we ask, and the answers, are put 

 into words, and we try to give the words the 

 clearest meanings we can. But they are no sub- 

 stitute for reality. They always fall short of 

 saying what needs to be said. Even after one 

 has learned to talk easily about nature in cer- 

 tain ways, after the words and phrases and con- 

 cepts have grown familiar, the contact with the 

 thing itself is always surprising. It has a quality 

 of newness and freshness; one feels that for the 

 first time one really understands — or, what is at 

 least as good, that one has never understood at 

 all — that the familiar words had been concealing 

 mysteries. Often it looks as though something 

 were being explained, when in fact it is only 

 being named. A lot of scientific terminology is 

 of this kind. It does well enough in a world of 

 words, but fails immediately in a world of 

 things. 



Nowhere is this as true as in biology. The 

 word "life" itself balks all attempts to define it. 

 The trouble is that whatever definitions of life 

 we make are easily fulfilled with models that 

 clearly are not alive. What we do about life is 

 not define it, but recognize it. It would be an 

 interesting experiment to see whether you could 

 be fooled now; whether if we showed you a lot 

 of different things, alive and dead, you would 

 have trouble telling the one from the other. 



In any case we hope you will do better after 

 your experiences in this laboratory; better, not 

 only in telling what is alive from what is dead, 

 but in knowing what to expect of living things. 



what they do, how they behave, what they can 

 tolerate, and what is likely to kill them. This 

 is what biologists sometimes talk about as "the 

 feel" of living organisms, something one gets 

 only by living with them — by observing, playing 

 with, and experimenting with them in their great 

 variety, until one has developed intuitions of 

 what kinds of things they do and don't do, and 

 what one can do and not do with them. Scien- 

 tists of all kinds — physicists, chemists, geolo- 

 gists, astronomers — are turning their attention 

 to biology as never before; and this is a fine 

 thing. Many biologists think, however, that 

 what some of these visitors lack is just this 

 "feel" for organisms. Sometimes they know 

 the words, but make obvious mistakes or miss 

 the point entirely, because they do not know 

 living organisms and do not have useful intui- 

 tions about them. 



Living organisms are made of molecules, and 

 it is important not only to develop a "feel" for 

 the organisms, but equally for the molecules 

 that compose them. They are for the most part 

 a special group of molecules, made almost ex- 

 clusively of carbon, hydrogen, nitrogen, and 

 oxygen — so-called organic molecules. All of 

 them are interesting, and all have special proper- 

 ties; but particularly the big ones, the proteins 

 and nucleic acids, have qualities of their own 

 that set them apart to a degree from all other 

 molecules. They are at once the largest and 

 most complicated molecules we know. Here 

 again the words fail. It is only by preparing 

 and handling them, by learning what they will 



