Vol. Ill, No. 3 



September, 1928 



The Quarterly Review 

 ; of Biology 



w 



THE GENE 



By RICHARD GOLDSCHMIDT 

 Kaiser Wilhelm Institut fur Biologie, Berlin-DaMm 



ITHOUT running the risk 

 of exaggerating the ge- 

 neticists may claim to have 

 finally settled the follow- 

 ing facts about the gene: i. its real 

 existence as a rather stable unit; 2.. its 

 position within the chromosomes of the 

 cell; 3. the orderly arrangement of the 

 genes within each chromosome; 4. the 

 transmission of the genes through the 

 generations of cells and individuals, gen- 

 erally without change of the nature of the 

 gene; 5. the connection of definite genes 

 as cause with every conceivable type of 

 morphological and physiological char- 

 acter in the organism as effect. Thus the 

 conception of the gene has become as firm 

 a basis for the study of heredity as the 

 conception of the atom for the study of 

 physics. The next problems which have 

 to be solved concern the nature of the gene 

 and its action in producing the hereditary 

 characters. The study of these problems 

 has only begun. There is at present no 

 way visible for a direct attack upon the 

 gene which could reveal its nature. Only 

 indirect ways are available, which might 

 lead to more or less definite conclusions. 



Already quite a number of facts have been 

 accumulated, which might serve as a 

 starting point for further investigation. 

 The following review will examine such 

 facts and try to correlate them. The 

 present writer has consistently worked in 

 this direction and developed definite 

 conclusions from experimental evidence, 

 which so far as he can see are still the only 

 ones covering the whole body of problems. 

 He may therefore be excused if his own 

 interpretations are placed in the fore- 

 ground. However, the facts which will 

 be recorded are facts, and everybody is 

 welcome to give them another interpre- 

 tation, provided it covers the same ground 

 and is a better one. 



A number of different ways are visible 

 for the attack on our problem. In our 

 opinion by far the best ought to be the 

 study of the effects of the same gene in 

 different quantities. If a gene has a 

 different effect when present in different 

 quantities and if these effects can be shown 

 to follow any law a very considerable 

 step will have been made towards the 

 understanding of the action of the gene. 

 This way of analysis was first opened by 



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QUjS a. KEV. BIOL., VOL. Ill, NO. 3 



