478 



persist. They will only demand the occasional presence in later em- 

 bryonic life, youth, adult, or old age of one or two such vagrant pri- 

 mary germ-cells, in order to account fully for their finds. 



Dermoid Cysts and Teratomata. 



This is the title of an important research by Prot. Max Wilms, 

 of the University of Leipzig. Not being a pathologist, the writer has 

 no knowledge of the effect produced in pathological circles by the 

 publication of this original investigation. It cannot be at all widely 

 known to Vertebrate embryologists. Had it been published in an em- 

 bryological journal as a developmental treatise, it would probably have 

 created an immense sensation. 



The author seeks to prove, and to my mind with complete success, 

 that the dermoid cysts, found in the ovary and testis in man and 

 mammals, are rudimentary embryos, or, as he terms them, "embryomas". 



Usually these pathological growths are made up of more or less 

 of the structures, or some of them, found in the head-end of a normal 

 embryo. Thus, hair, sebaceous and sweat-glands seem always to be 

 present. Membrane bones and nerve-matter may also obtain; rarer 

 are teeth and rudiments of forelimbs. That is, they represent embryo- 

 logically a greater or less portion of the anterior end of an embryo^). 



As it is proposed to review Wilms' work ^) from the embryo- 

 logical standpoint elsewhere, and to include in this one or two other 

 recent papers, a brief notice may suffice here. My object now is to 

 direct the attention of embryologists to his researches; and to point 



1) Through the kinduess of a friend and former pupil, Principal 

 Mettam, B. Sc., of Dublin Royal Veterinary College, an exquisite and 

 typical example, found on castration in the testis of a young horse, 

 has recently come into my hands. 



2) Max Wilms, Ueber die Dermoidcysten und Teratome etc. 

 Deutsch. Arch., f. klin. Med., Bd. 55, 1895, p. 1—108, 3 Tab. Wilms 

 restricts, as noted in the text, the name "embryoma" to the dermoid 

 cysts of the ovary and testis. From evidences contained in his own 

 work it appears clear, that this limitation cannot be carried out. The 

 case, recorded bj^ Sloman and cited by Wilms on p. 9, is an instance 

 of a true "embryoma" in another part of the body, and this example 

 does not stand alone. My position, regarding the embr3'omas, is this, 

 that they may occur in almost any part of the body, but that, naturally, 

 they are far more numerous in ovary and testis. They always 

 arise from persistent primary germcells. An account of 

 Wilms' work, written by himself, has recently appeared in Martin's 

 "Die Krankheiten der Eierstücke etc.", Leipzig 1899, p. 576 — 614. 



