ANIMAL BIOLOGY 



CHAPTER I 

 THE SCOPE OF BIOLOGY 



Science is, in its source, eternal; in its scope, immeasurable; in its 

 problem, endless; in its goal, unattainable. — von Baer. 



The oldest as well as the most obvious classification of the ob- 

 jects composing the world about us is into non-living and living; 

 and the knowledge accumulated during many centuries in regard 

 to the former is to-day represented in the physical sciences, while 

 that of the latter comprises the content of biology, the science 

 of matter in the living state. Biology, like all science, has as its 

 ultimate object the description of its phenomena in terms of what 

 may be regarded as basic concepts — matter and energy acting 

 in space and time; but it is needless to say that the attainment of 

 this object is not imminent in any department of knowledge, and 

 least so in the science of living things. These exhibit a state of 

 matter and energy which altogether transcends the classifications 

 of physicist and chemist to-day — a condition which expresses 

 in its highest manifestations what we call our 'life.' 



Whether the ' riddle of life ' will ultimately be solved is a question 

 which everyone would like to answer but only the rash would at- 

 tempt to predict. Suffice it to say that biologists who are on the 

 firing line of progress to-day are directing their attention solely 

 to the description and measurement of the phenomena exhibited 

 by living things — those phenomena which distinguish life from 

 lifeless — in an attempt to relate them to the familiar and more 

 readily accessible phenomena of which we have some exact knowl- 

 edge in the realm of the non-living. But this should by no means 

 be taken to indicate that biologists do not recognize the stupen- 

 dous problems they face, or do not appreciate to the full — indeed 

 more fully than others — the enormous gap that separates even 

 the simplest forms of life from the inorganic world. 



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