100 HEREDITY. 



shall be brought into existence right side up. As- 

 suredly, your affinities must be very peculiar forces. 

 Can they be simply chemical and mechanical, and yet 

 adequate to their work ? How is it that the gem- 

 mules seem to be possessed of an inflexible purpose 

 of coming together in the right form, so that the 

 animal shall be built up 1, 2, 3, and not 3, 2, 1? 

 What if the first number should drop into the mid- 

 dle? Nothing but mechanical and chemical forces 

 here, Huxley affirms ! Darwin refuses in his theory 

 of pangenesis to employ any other word than " affin- 

 ity." To talk about other forces would be like 

 talking of the horologity of a clock! 



If the affinities which bring the gemmules together 

 in the right order are merely chemical, they are 

 forces of a kind chemistry knows nothing of any- 

 where else. Here is a species of affinity that exists 

 only in germinal matter. Even in that kind of 

 matter, which to all human tests is chemically the 

 same in many different kinds of germs, the plans of 

 the affinities differ as endlessly as the types of life. 



If, now, you will multiply the three parts of this 

 small organism, thus far used as an illustration* by 

 a number representing the multitudinous parts in 

 the most highly organized animal, and apply the 

 same law of descent, you have Darwin's theory of 

 pangenesis. We have here [drawing a figure on the 

 blackboard], let us suppose, the outlines of some 

 highly complex form of organism ; I care not what 

 the foot of a frog, or the palm of my hand. It is a 

 mass of interlaced living tissues, and it is crossed in 



