ANATOMY OF A MONODACTYLOUS FOETUS 417 



uterus, and so being one cause of the condition to which Mall 

 ascribes most pathological embryos. To show that attempts at 

 abortion form a cause not to be neglected in this regard I quote 

 from the Secretary of the Indiana State Board of Health, Dr. 

 J. N. Hurty ('17) who says "It has been estimated that about 

 one-third of pregnancies end in induced abortions, that at least 

 200,000 volitional abortions occur every year in the United 

 States and that not less than 12,000 women die annually from 

 the direct effects thereof." (This is quoted from another article 

 as I regret I have been unable to obtain the journal with Dr. 

 Hurty's original article in it.) Surely the arguments I have 

 used above are sound in view of such conditions as Hurty states 

 to exist and attempted abortions which are not immediately 

 successful ought to be ranked amongst the causes of pathological 

 embryos and monstrosities. 



Some of the abnormal conditions found in this foetus can be 

 correlated with interesting embryological stages of growth which 

 it seems to me throw considerable light on what are otherwise 

 obscure isolated facts. Statements as to normal skeletal and 

 muscular development are taken from the accounts by Bardeen 

 and Lew^is in Keibel and- Mall's Human Embryology. ('10). 



In the early development of the vertebra, as the scleroblas- 

 tema becomes chondrified, this process in the bodies of the verte- 

 brae is brought about by two centers, one on each side of the 

 notochord. At first there is no fusion of these two centers of 

 chondrification dorsally or ventrally around the notochord, as 

 there is present in the mid line a membranous perichordal sep- 

 tum (Keibel and Mall). Normally this septum is soon broken 

 through both dorsally and ventrally and the notochord is com- 

 pletely surrounded by cartilage by about the fifth or sixth w^eek. 



Ossification then occurs from a center which is usually single, 

 but may divide or even arise paired. 



The early presence of the perichordal septum appears signifi- 

 cant in view of the fact that in this foetus are found two verte- 

 brae with divided bodies, each half growing independently, and 

 one-half growing less rapidly than normal. This septum was 

 present at the period of embryonic life when that vice of develop- 



