ELEVENTH EEPORT ON RECENT TERATOLOGICAL LITERATURE. 499 



die, or having been originally deformed, cease to grow, wliile the 

 amnion, cord, and chorion grow on as if nothing had happened. 

 The earliest stage of this form of degeneration is represented 

 in an embryo which consists of a very atrophic head only, seated 

 upon the tip of the umbilical cord within the amnion. The umbilical 

 vesicle is attached to the side of the cord but does not in any 

 way extend to the embryo. Again, there are other cases in which 

 the ova are normal in outward appearance in every way but 

 contain no embryos. All the above-mentioned forms of defect may 

 be explained as forms of arrested development of the embryo, 

 its partial or its complete desti'uction. The writer finally considers 

 the very puzzling group of vesicular embryos, of which it has 

 always been asserted that they are early pathological embryos. 

 All the specimens at the author's disposal indicated in every way 

 that the vesicle is the umbilical, for in it are found .the characteristic 

 mesoderm with blood-vessels filled with blood. Rabaud (viii.) 

 has a paper on regeneration and ricatrhation in their relation 

 to embryonic development, in which, after a general survey of 

 the problems connected with the subject, the author concludes 

 that regeneration is affected according to the laws of phylogenetic 

 development, i.e. in obedience to the exigencies of the derivation 

 of the layers. Ballantynb (ix.) has an interesting paper on the 

 pathology of the germi?ial period of antenatal life, which he says 

 ends with the first appearance of the embryo in the embryonic 

 area of the blastodermic vesicle. In this period he considers 

 that morbid causes are chiefly effective in producing tendencies 

 which may afterwards become monstrous developments or non- 

 developments, or diseases ; while in the later period these results 

 are doubtless still produced, but in addition there has to be taken into 

 account the production of twins and united terata, and perhaps 

 also of neoplasms, certainly of teratomata. The same author (x.) 

 in another paper describes a case of re.'urrent monstriparity in a 

 woman the subject of hereditary malformation of the muscles 

 of the thumb as well as of other abnormalities. Fere (xi.) gives 

 an account of an arred of developvient in tJie area opaca of the 

 chick, which affected its entire extent. Lenormant and Durand- 

 ViEL (xii.) give an account of a case of complete inversion of the 

 viscera in a female aged 22, in whom the great vessels of the 

 thorax were also displaced. 



Fere (xiii.) gives evidence to show that the amnio7i is not re- 

 sponsible alone for the separation of parts of the foetal body. He 

 has found two eggs in one of which the head Avas separated from 

 the body and in the other both the cephalic and caudal extremities 

 were atrophic. In neither of these instances could the amnion have 

 been responsible, for in both it formed a large sac round the embryo. 

 Eertacchini (xiv.) narrates another case of so-called iiudemal iiU' 

 pression, and generally discusses the subject. Rabaud (xv.) describes 

 tiro new conditions allied to ompha'ocephaly, which he calls ourentery 

 and cordentery. He proposes to form a new group called Enentcrians, 

 i.e. cases in which some part of the embryo is abnormally lodged in 



