68 FRANKLIN P. MALL 



pregnancy. One monster at term, a sympus belonging in 

 about the third hundred, was not recorded in our catalogue, 

 and should be added to the four full term specimens given in 

 table 4. This means that among 1001 specimens there were 

 five monsters at term, while among 1000 specimens there were 

 71 with localized anomalies, most of which w^ere aborted early 

 in pregnancy. 



According to the table on the frequency of abortions given in 

 my monograph on monsters,^ there are 80 full term births for 

 each 20 abortions; therefore, the 1000 abortions under considera- 

 tion were probably derived from 5000 pregnancies. 



As we have calculated that there should be approximately 30 

 full term monsters in 5000 pregnancies, and as 5 of these were 

 observed in our 1000 specimens, it is apparent that the remain- 

 ing 25 should be encountered in 4000 additional full term births. 

 When these figures are compared with the fact that 75 localized 

 anomalies occurred in 1000 abortions — 7.5 per cent, it becomes 

 apparent that in any similar numbers of abortions, localized 

 anomalies should be noted twelve times as frequently as mon- 

 sters at term. A similar result is obtained if the number of 

 localized anomalies of the tenth month, as given in table 4, is 

 compared wdth all of the localized anomahes of pre\dous months, 

 as given in the same table." 



Our studies seem to justify the conclusion that pathological 

 embryos, as well as those which are normal in form, are very 

 frequently associated with localized anomalies and that abortion 

 usually follows as a result of serious lesions in the chorion, as 

 well as in its environment. Should the alterations in the em- 

 bryo and in the chorion be very slight, and the condition of the 

 uterine mucous membrane, which may be expressed by the 

 term inflammation, be overcome, the pregnancy in all proba- 

 bility would go to term and end in the birth of a monster or 

 an infant presenting a well recognized malformation. 



^ Also in a resume of the paper on monsters in the article entitled: Mall, F. 

 P. Pathology of the human ovum. Chapter 9, Human Embryology, Keibel and 

 Mall, vol. 1, 1910. 



® Records are now being made of about 50,000 births in Baltimore, including 

 the frequency of abortions for each mother. When these are completed, the 

 above mentioned ratio of 1 to 4 will probably be changed. 



