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TEE AMERICAN NATURALIST [Vol.LVI 



the autocatalysis is an expression of specific attractions 

 between portions of the gene and similar protopLasmic 

 building blocks (dependent on their force-field patterns), 

 it is evident that the very same forces which cause the 

 genes to grow should also cause like genes to attract each 

 other, but much more strongly, since here all the indi- 

 vidual attractive forces of the different parts of the gene 

 are summated. If the two phenomena are thus really 

 dependent on a common principle in the make-up of the 

 g^ne, progress made in the study of one of them should 

 help in the solution of the other. 



Great opportunities are now open for the study of the 

 nature of the synaptic attraction, especially through the 

 discovery of various races having abnormal numbers of 

 chromosomes. Here we have already the finding by 

 Belling, that where three like chromosomes are present, 

 the close union of any two tends to exclude their close 

 union with the third. This is very suggestive, because the 

 same thing is found in the cases of specific attractions 

 between inorganic particles, that are due to their force 

 field patterns. And through Bridges ' finding of triploid 

 Drosophila, the attraction plicnoiiK'na can now be brought 

 down to a definitely uvni<- bn^is. by th(^ introduction of 

 specific genes— ,es]itM-ially ilu..,. known to influence chro- 

 mosome behavior— into one of the .•lii'oniosome. of a 

 triad. The amount of influence of tliis -en., on ntt i nction 

 may then be tested quantitatively, I»y -vncti.' dct-Tmina- 

 tion of the frequencies of the various ])os>ibl(' tyju-s of 

 segregation. By extending such studies to include the 

 effect of various conditions of the environment— such 

 as temperature, electrostatic stresses, etc.— in the pres- 

 ence of the different genetic situations, a considerable 

 field is opened up. 



This suggested connection between chromosome behav- 

 ior and gene structure is as yet, however, onlv a ].(>.- 

 sibility. It must not be forgotten that at pre...,i't uv ,-ui 



