The Origin of Heredity 229 



influences which work upon the organism as a whole, 

 and reach the reproductive cells as well as the body tissues. 

 But to accomplish the transmission of specific modifica- 

 tions of particular parts, a very complex special mechan- 

 ism would be necessary, whereby the part affected in the 

 parent would impart some sort of special modification to 

 the germ-cells, which would in turn cause the same modifi- 

 cation of the same part in the offspring (cf. the address 

 of Sedgwick before the British Association, in Nature, 

 Sept. 21, 1899). 



It may also be suggested that such a complex mechanism 

 of transmission would be a highly specialized adaptation, 

 and if such a mechanism be necessary to Lamarckian 

 heredity, it would itself have to be accounted for without 

 such heredity. But the rise of complex adaptations is the 

 point at issue. 



3. The Origin of Heredity 



This question takes on considerable importance in view 

 of recent discussion of the origin of heredity itself, in con- 

 nection with researches into variation. Heredity means, of 

 course, more or less lack of variation what is called 

 1 breeding true ' to stock from parent to offspring ; it is 

 the opposite of variability, which is departure from the 

 ' true ' or like. It has generally been assumed that hered- 

 ity, at least in the simple form seen in cell-division, the 

 so-called daughter-cells being parts of the original mother- 

 cell, was an original property of living matter, and 

 variation from the true was the phenomenon to account 

 for. Recently, however, the theory has been advanced by 

 Bailey {Plant Breeding, 1895, and especially Survival of 

 the Unlike, 1896) and Williams (Geological Biology; 



