THE ARGUMENT FROM DISEASE 161 



270. " These results from pigeons suffering from malaria 

 seem to indicate that the germ-cells are liable to be influenced 

 by fevers and other forms of disease that for the time being 

 diminish the vitality of the parents. Further experiments 

 may show that the germ-cells are influenced in different ways 

 by different diseases. 



271. " Sometimes the germ-cells suffer from the direct action 

 of their immediate environment, from disturbance in or 

 around the germ-glands. If, for example, inflammation by the 

 ducts or other channels reaches the germ-glands, the vitality 

 of the germ-cells may be considerably diminished ; if serious 

 or prolonged, the germ-cells may be as effectively sterilized 

 as are the bacteria of milk by boiling. 



272. "In 1900 two mares produced foals to a bay Arab 

 which had previously suffered from a somewhat serious 

 illness involving the germ-glands. The foals in no way 

 suggest their sire. This year I have three foals from the 

 same Arab after he had quite recovered ; one promises to be 

 the image of his sire, and the other two are decidedly Arab- 

 like both in make and action. 



273. " While all the germ-cells are liable to suffer when 

 the soma is the subject of disease, there is no evidence that 

 they are capable of being so influenced that they transmit 

 definite or particular modifications (unless directly infected 

 by bacteria or other minute organisms) ; that, e. g., the germ- 

 cells of gouty subjects necessarily give rise to gouty offspring. 

 Doubtless if the germ-cells, because of their unfavourable 

 immediate surroundings, suffer in vigour or vitality, the off- 

 spring derived from them are likely to be less vigorous, and 

 hence more likely than their immediate ancestors to suffer 

 from gout and other disease." 



274. The foregoing passages are quoted in full, since they 

 contain evidence which is, probably, more conclusive, or at 

 any rate more easy to handle, than any in medical literature. 

 Owing to the less complex conditions, the danger of confus- 

 ing post hoc with propter hoc is smaller. It must be admitted 

 that Professor Ewart has proved that, for the time being, 

 prepotency is affected by the condition of the germ-cells. 

 But, though lack of health and vigour in the germ-cells of 

 one parent may cause the characters of the other parent 

 to preponderate in the offspring, yet no traits new to both 

 parents arise in the offspring. Moreover, the suppressed 

 traits are not necessarily lost to the species. It is very 

 probable that they are rendered merely latent, and that they 



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