STRUCTURE AND DEVELOPMENTAL RATE 227 



cent of the ectopic specimens were of this nature. The double 

 frequency of pathological specimens in ectopic pregnancies 

 shows at once the influence of unfavorable environment. These 

 facts are of primary importance and Mall discusses them in a 

 most instructive way. He states, to account for human monsters : 

 ''It would have been quite simple to conclude that the poisons 

 produced by an inflamed uterus should be viewed as the sole 

 cause, but when it is recalled that pathological ova occur far more 

 commonly in tubal than in uterine pregnancy, such a theory be- 

 comes untenable." It is then stated further: "For this reason 

 (meaning the records from ectopics) I have sought the primary 

 factor in a condition buried in the non-committal term, 'faulty 

 implantation.' " The faulty implantation acted to injure the 

 development, in Mall's opinion, on account of supplying insuf- 

 ficient nutriment. I should be inclined to accept the faulty 

 implantation as the primary factor, but the injm-ious effects of 

 such an arrangement are due to an insufficient oxygen rather than 

 food supply. This difference in interpretation is only of aca- 

 demic value. Malnutrition effects developing individuals in a 

 general way causing a condition of undersize, while insufficient 

 oxygen decidedly slows the rate or may completely interrupt 

 development and thereby induces various structural deformities. 



Mall in this paper is inclined to drop the cruder term 'nutrition' 

 and admits that, "Probably it would be more nearly correct to 

 state that change in environment has affected the metabolism 

 of the egg." This would be entirely in accord with the interpre- 

 tation e! arrest as being due to lowered oxygen supply. 



Again, Mall reaches significant conclusions when considered 

 in connection with the foregoing general principles of abnormal 

 development. For, on page 72, he states: "Accordingly, when 

 an embryo through changed environment is profoundly affected, 

 the development of one part of the body may be arrested, while 

 the remaining portion may continue to grow and develop in an 

 irregular manner. In very young embryos, tissues or even entire 

 organs may become disintegrated, as can easily be recognized by 

 the cytolysis and histolysis present, and the resultant disorgan- 

 ized tissue cannot continue to produce the normal form of an 



