1 6 HEREDITY AND INHERITANCE 



heredity as statisticians are, indeed more so ; statistical results are 

 based on individual data, but they do not admit of individual 

 application.] 



" Living matter has the special property of adding to its bulk 

 by taking up the chemical elements which it requires and building 

 up the food so taken as additional living matter. It further has the 

 power of separating from itself minute particles or germs which 

 feed and grow independently and thus multiply their kind. It is 

 a fundamental character of this process of reproduction that the 

 detached or pullulated germ inherits or carries with it from its 

 parents the peculiarities of form and structure of its parent. This 

 is the property known as Heredity. It is most essentially modified 

 by another property — namely, that though eventually growing to 

 be closely like the parent, the germ (especially when it is formed, 

 as is usual, by the fusion of two germs from two separate parents) 

 is never identical in all respects with the parent. It shows Variation. 

 In virtue of Heredity, the new congenital variations shown by a 

 new generation are transmitted to their offspring when in due time 

 they pullulate or produce germs." — E. Ray Lankester, Kingdom 

 of Man, 1907, p. 10. 



" By inheritance we mean those methods and processes by which 

 the constitution and characteristics of an animal or plant are handed 

 on to its offspring, this transmission of characters being, of course, 

 associated with the fact that the offspring is developed by the 

 processes of growth out of a small fragment detached from the 

 parent organism." — R. H. Lock, Recent Progress in the Study of 

 Variation, Heredity, and Evolution, 1906, p. 1. 



" Heredity. — The transference of similar characters from one 

 generation of organisms to another, a process effected by means of 

 the germ-cells or gametes." — Lock, op. cit. p. 292. 



§ 5. The Problems Illustrated 



Even in ancient times men pondered over the resemblances 

 and differences between children and their parents, and wondered 

 as to the nature of the bond which links generation to generation. 

 But although the problems are old, the precise study of them is 

 altogether modern. The foundations of embryology had to be 

 laid, the nature and origin of the physical basis of inheritance 



