1 88 TRANSMISSION OF ACQUIRED CHARACTERS 



Misunderstanding YII— Changes in the germ-cells along with 

 changes in the body are not relevant. — Another misunderstanding 

 is due to a failure to appreciate the distinction between a change 

 of the reproductive cells along with the body, and a change 

 in the reproductive cells conditioned by and representative 

 of a particular change in bodily structure. The supporters of 

 the hypothesis that modifications may be transmitted point 

 to the tragic cases where some poisoning of the parent's system, 

 by alcohol, opium, or some toxin, is followed by some deteriora- 

 tion in the offspring. There is no doubt as to the fact; the 

 question is as to the correct interpretation. 



(i) In some cases it may be that the whole system of the 

 parent is poisoned — reproductive cells as well as body ; the 

 effect may be as direct on the germ-cells as on the nerve-cells. 

 These, therefore, are not cases on which to test the transmissi- 

 bility of an acquired character — i.e. of a particular somatic 

 modification. If a local poisoning had a structural effect on 

 some particular organ, and if that structural effect was repro- 

 duced in any degree in the offspring, the case would be relevant ; 

 but when the whole organism is soaked in a poison the case is 

 irrelevant. If it could be said that the sunshine, which brings 

 about sun-burning in the skin, soaks through the organism even 

 to its reproductive cells and specifically affects them, in a 

 manner analogous to the saturating poison, we should have a 

 physiological basis for expecting the inheritance of sun-burning. 

 But we cannot make this assumption. We have no warrant 

 for believing that the modification of a part re-echoes in a definite 

 specific way through the organism until even the penetralia of 

 the germ-cells reverberate. 



(2) A parent organism is poisoned, and there are structural 

 results of that poisoning. The offspring are born poisoned, 

 and show similar structural peculiarities. This may be due 

 to the fact that the germ-cells were poisoned along with the 

 parental body ; but it may also be due, in the case of a mother, 



