darwin's theory of pangenesis. 103 



of atoms and forces, and, with no co-ordinating power 

 outside of itself, goes unerringty to its destination. 

 There is your theory of pangenesis complete. 



Let me now give you Darwin's own language : — 

 " It is universally admitted that the cells or units 

 of the body increase by self-division or proliferation, 

 retaining the same nature, and that they ultimately 

 become converted into the various tissues and sub- 

 stances of the body. But, besides this means of 

 increase, I assume that the units throw off minute 

 granules, which are dispersed throughout the whole 

 system ; that these, when supplied with j)roper nutri- 

 ment, multiply by self-division, and are ultimately 

 developed into units like those from which they were 

 originally derived. These granules may be called 

 gemmules. They are collected from all parts of the 

 system to constitute the sexual elements, and their 

 development in the next generation forms a new 

 being ; but they are likewise capable of transmission 

 in a dormant state to future generations, and may 

 then be developed. Their development depends on 

 their union with other partially developed or nascent 

 cells, which precede them in the regular course of 

 growth. Gemmules are supposed to be thrown off 

 by every unit or cell, not only during the adult state, 

 but dnv'mg>each stage of development of every organ- 

 ism ; but not necessarily during the continued exist- 

 ence of the same unit. Lastly, I assume that the 

 gemmules in their dormant state have a mutual affin- 

 ity for each other, leading to their aggregation into 

 buds or into the sexual elements. Hence it is not the 



