3 1 8 Appendixes 



3. We do not yet know whether independent redupli- 

 cated systems can be formed in the same individual. In 

 the sweet pea for instance we have not yet seen the 

 consequences of combining blue, erect standard, and long 

 pollen with the fertile-sterile, dark-light axil series, and 

 much may be discovered when such families come to be 

 examined. 



The phenomena seen in animals may well be produced 

 by the segmentations in which the parts of the ovary or 

 testis are determined. Hitherto no case of coupling has 

 been found in animals. Among the phenomena of repulsion, 

 however, of which many examples exist, certain suspicious 

 cases have been observed which may mean that in animals 

 reduplicated systems exist like those of the plants. Never- 

 theless at present it seems not impossible that the two 

 forms of life are really distinguished from each other in 

 these respects. 



Lastly, in view of what we now know. It Is obvious 

 that the terms "coupling" and "repulsion" are misnomers. 

 " Coupling " was first introduced to denote the association 

 of special factors, while '' repulsion " was used to describe 

 dissociation of special factors. Now that both phenomena 

 are seen to be caused not by any association or dissociation, 

 but by the development of certain cells in excess, those 

 expressions must lapse. It is likely that terms indicative 

 of differential multiplication or proliferation will be most 

 appropriate. At the present stage of the inquiry we 

 hesitate to suggest such terms, but the various systems 

 may conveniently be referred to as examples of reduplica- 

 tion, by whatever means the numerical composition of the 

 gametic series may be produced. 



It remains to be seen whether systems of reduplication 

 not contemplated by this scheme will be proved to exist, 

 but it should be mentioned that Baur has already shown 

 the probability that other ratios, especially 6:1:1.6, 

 occur In A^itii^rhinum (see Zts. f. ind. Abstam., 1912, vi. 

 p. 201) ; and once It is realized that the phenomenon is 

 probably one of reduplication of certain terms, there seems 

 no reason for supposing that various less simple series will 

 not be found. 



