16 LIVERPOOL BIOLOGICAL SOCIETY. 
finally develop into cells it is as a result of their affinity for allied gemmules 
produced before them, and which have just attained their full development.’’* 
In 1876, Mr. Francis Galton+ proposed a most important 
modification of Pangenesis to the effect that out of the 
total number of gemmules contained in the fertilized 
ovum, and to which collection he applies the term “‘stirp,”’ 
only a few develope in that generation into cells, while 
the rest form a mass of dormant gemmules which are 
handed on from generation to generation by the repro- 
ductive elements, a few of the gemmules developing in 
each generation into cells and so conveying to the 
individuals of that generation ancestral characteristics. 
This idea of a certain portion of hving matter which is 
immortal, being passed on from generation to generation, 
and forming a connecting link between ancestors and their 
posterity, has been adopted by nearly all subsequent writers 
on heredity, and most of the recent speculations may 
therefore be regarded as modifications of Galton’s theory. 
In 1883, in a paper read before the Literary and Philo- 
sophical Society of Liverpool, entitled ‘“‘Remarks upon 
the Theory of Heredity,’ { I proposed a modification of 
Galton’s theory, which I believe relieved it of a difficulty 
under which it had laboured. My addition to the theory 
was, ‘‘that the body of the new indwidual ts formed, not by 
the development of gemmules alone and independently into 
cells, but by the gemmules in the cells causing by their 
affimties and repulsions these cells so to diwide as to gwe 
rise to new cells, tissues and organs.’ This suggestion gets 
over the histological difficulty that cells are always formed 
from pre-existing cells and not from gemmules, and it 
likewise places the theory of heredity in direct connection 
* Variation of Plants and Animals under Domestication, vol. ii., p. 357, 1868. 
+ Journ. Anthropol. Instit., vol. v., p. 329. 
+ Proc. Lit. and Phil. Soc., L’pool, vol. xxxviii., p. 77, read Noy. 26th, 1883. 

