DARWIN AND THE ORIGIN OF SPECIES 251 



able complexity of algebraic arrangement can approach the 

 complexity of the laws which regulate the construction of an 

 organic being out of inorganic elements ? Let the chemist tell 

 us the laws of combination of each substance found in an or- 

 ganised being. Let us next attempt to conceive the complexity 

 of the conditions required to arrange these combinations in 

 a given order, so as to constitute an eating, breathing, moving, 

 feeling, self-reproducing thing. When our mind has recoiled 

 baffled, let us consider whether it is not probable, nay cer- 

 tain, that there should be a limit to the possible number of com- 

 binations, called animals, or vegetables, produced out of a few 

 simple elements, and grouped under the above inconceivably 

 complex laws. Next, we may ask whether, as in the mathe- 

 matical permutations, combinations, and arrangements, the com- 

 plete set of possible organised beings will not necessarily form a 

 continuous series of combinations each resembling its neighbour, 

 even as the letters of the alphabet, grouped say in all possible 

 sets of five each, might be arranged so as to form a continuous 

 series of groups, or sets of series, according as one kind of 

 resemblance or another be chosen to guide us in the arrange- 

 ment. It is clear that the number of combinations or animals 

 will be immeasurably greater when these combinations are 

 allowed to resemble each other very closely, than when a con- 

 dition is introduced, that given marked differences shall exist 

 between them. Thus, there are upwards of 7,890,000 words or 

 combinations of five letters in the English alphabet. These are 

 reduced to 26 when we insert a condition that no two combi- 

 nations shall begin with the same letter, and to 5 when we 

 stipulate that no two shall contain a single letter alike. Thus 

 we may expect, if the analogy be admitted, to find varieties of a 

 given species, apparently though not really, infinite in num- 

 ber, since the difference between these varieties is very small, 

 whereas we may expect that the number of well-marked pos- 

 sible species will be limited, and only subject to increase by the 

 insertion of fresh terms or combinations, intermediate between 

 those already existing. Viewed in this light, a species is the 

 expression of one class of combination ; the individuals express 

 the varieties* of which that class is capable. 



It may be objected that the number of elements in an organ- 



