ORIGIN OF MONSTERS 561 



hand and the occurrence of monsters in man on the other hand 

 would seem to point to the correctness of our conclusions. 

 Besides, many monsters similar to human monsters are found 

 in other mammals (and in sauropsids) which are neither ex- 

 posed to the dangers of alcohoUsm nor to those of 'industrial 

 diseases.' These considerations have led me to believe that 

 poisons such as alcohol and other drugs as well as poisons of 

 the 'occupational diseases' only very rarely, if ever, may lead to 

 monstrous development in nature. The percentage of monsters 

 whose origin may be due to these causes must, at best, be re- 

 garded as so small, as to be practically negligible. 



Let us now turn to the next known chemical modification of 

 the mammalian body, namely to the toxines of infectious diseases. 

 Is there any likehhood that such toxines, when present in the 

 blood of a female, would have such a deleterious effect on the 

 ovum in its uterus, as to seriously derange the course of its 

 development? This question is as yet difficult to answer, for 

 the existing data on the subject are too insufficient and too 

 indefinite. But even if future researches should prove the 

 probability of a deleterious effect of maternal infectious diseases 

 on the embryo in utero, which at present seems doubtful, there 

 would remain only one other great source of chemical alteration 

 of the ovum's environment, namely the products of pathologic 

 metabolism. Of the latter there is a considerable number known 

 at the present time, and a better knowledge of the pathological 

 chemistry of disturbances of, particularly, proteid metabolism 

 may add to this number. 



Already Forster ('65) has advanced the hypothetical view 

 that chemical alteration of the maternal blood may be one of 

 the causes underlying the origin of monsters. This view although 

 — strangely enough — almost entirely overlooked is now, however, 

 not insupportable. For, recent advances in pathological chem- 

 istry have made us famifiar with the chemical changes which 

 our organism is subject to under certain pathological conditions. 

 At the same time a better insight has been gained into the close 

 physiological relation existing between the developing embryo 

 and the mother. Thus, in the light of our present knowledge 



