112 THEORETICAL BIOLOGY 



at hand. It was reserved for Darwinism to assert that the 

 morphological principles are referable to the physiological 

 principles of earlier generations. 



As a tangible proof of this very dubious theory, Darwinism 

 discovered the "vestigial organs" said to be demonstrable 

 in every individual now living as surviving remains of physio- 

 logical requirements in past ages. 



It is true that we sometimes see human tools, converted to 

 other purposes, still retaining from the past certain useless 

 parts that do not happen to be inconvenient. Thus when 

 old railway-carriages are turned into workmen's dwellings, 

 the wheels, now useless, are not removed, but are merely 

 fixed so that they do not turn. 



On the basis of such a superficial analogy, it has straight- 

 way been assumed that there might be vestigial organs with 

 only a morphological, but no functional significance. Hitherto 

 no single one of these organs has withstood careful testing ; 

 some function peculiar to it has always been revealed, and it 

 is to be hoped that " vestigial organs " will soon disappear 

 into oblivion. It is surely presumptuous to thrust on biology 

 a theory according to which an absolutely useless tumour 

 (which is what the vestigial organ represents, from the physio- 

 logical standpoint) must be inherited for thousands of years 

 throughout all generations. 



Apart, however, from this lapse in recent times, mor- 

 phology has established very remarkable and stable rules, 

 and to these we must unconditionally accord special import- 

 ance. When, for instance, we find that the whale and the 

 giraffe, which are both mammals, have the same number 

 of cervical vertebrae, namely 7 (and this despite the ex- 

 tremely different length of their necks), but that the swan 

 has more than 20, then morphology is completely justified 

 in claiming to use its rules as indications for the determination 

 of relationship. But the nature of the connection between 



