D INTRODUCTION. 



The accompanying plates were carefully drawn by the artist, 

 Richard Scholz, exactly true to nature and without any attempt 

 to obtain a diagramatic effect. 



I wish to thank the artist, as well as the publisher, for the ex- 

 cellent reproduction of these figures and for the valuable ser- 

 vices they have thereby rendered science. 



There will be considered: 



1st. The Decidua Vera. 



2nd. The Implantation of the Ovum with the formation of 

 the capsularis and the fibrinous covering, which lies over the 

 ovum on the mucous membrane. ("Gewebspilz" of Peters.) 



3rd. The "Eianlage" and the Ovular Chamber "Eikammer." 



4th. The Trophoblast and its surrounding blood spaces. 



5th. The Syncytium. 



A germinal plate which was found in Peters' specimen could 

 not be discovered in any of the sections of this new ovum. 

 Whether its absence be possibly due to the general phosphorus 

 poisoning must remain an open question until more specimens 

 of such an early stage are obtained. It must be remembered 

 that the woman from whom the Peters ovum was obtained, also 

 committed suicide, but with caustic potash, which is capable of 

 producing a very acute hyperemia of the mucous membrane of 

 the pelvic organs. 



Some of the ova described by Marchand, Rossi Doria, Graf 

 von Spec, Heukelom, Mertens, etc., can hardly be pronounced 

 normal specimens free of objections. The indications for the 

 post mortem in such instances will necessarily be either a suicide 

 or an acute illness caused by poisoning or some intercurrent dis- 

 ease (such as pneumonia, burns, etc.), or a disease of the sexual 

 organs necessitating a removal of the uterus. All of these con- 

 ditions, especially in the early stages of pregnancy, will hardly 

 ever fail to lead to some changes in the circulatory apparatus of 

 the uterus. Nevertheless some portions of both the uterus or the 

 ovum may be found in a very satisfactory state of preservation. 



Of the three young ova described by Marchand, the first had 

 a defective fibrinous capsule, supposedly injured during a curet- 

 age. The second was infiltrated with blood and yet Marchand 

 did not hesitate to investigate these defective specimens, to study 

 such difficult problems as the trophoblast and the syncytium and 

 finally drew, although with great precaution, certain conclu- 

 sions. 



In order to satisfy myself of the value of this specimen I sub- 

 mitted several sections to my esteemed colleagues, Obermedizin- 

 alrat Prof. Dr. Schmorl and Prof. Graf von Spec in Kiel, whom 



