CONSTRUCTION OF THE PEDIGREE. ^J 



employing the empirical results of embryology, palaeon- 

 tology, and anatomy for supplementing each other, we 

 arrive at an approximate knowledge of "the Natural 

 System," which, according to our views, is the pedigree of 

 organisms. It is true that our human knowledge, in all 

 things fragmentary, is especially so in this case, on account 

 of the extreme incompleteness and defectiveness of the 

 records of creation. However, we must not allow this to 

 discourage us, or to deter us from undertaking this highest 

 problem of biology. Let us rather see how far it may even 

 now be possible, in spite of the imperfect state of our 

 embryological, palseontologieal, and anatomical knowledge, 

 to establish a probable scheme of the genealogical relation- 

 ships of organisms. 



Darwin in his book gives iis no answer to these special 

 questions of the Theory of Descent ; at the conclusion he 

 only expresses his conjecture "that animals have de- 

 scended from at most only four or five progenitors, and plants 

 from an equal- or less number." But as these few aboriginal 

 forms still show traces of relationship, and as the animal 

 and vegetable kingdoms are connected by intermediate tran- 

 sitional forms,, he arrives afterwards at the opinion " that 

 probably all the organic beings which have ever Kved on 

 the earth have descended from some one primordial form, 

 into which life was first breathed by the Creator." Like 

 Darwin, all other adherents of the Theory of Descent have 

 only treated it in a general way, and not made the attempt 

 to carry it out specially, and to treat the " Natural System " 

 actually as the pedigree of organisms. If, therefore, we 

 venture upon this difficult undertaking, we must take up 

 independent ground. 



