122 SIXTH REPORT 1836. 



since, he has fully satisfied himself and others, who have examined the 

 part with him, or to whom he has exhibited it in his lectures on em- 

 bryology, both of its existence and peculiar character. 



There are on the external or uterine surface of the decidua vera a 

 great number of small cup-like elevations, which project from it. They 

 are like little bags, the bottoms of which are attached to or embedded 

 in the Substance of the decidua ; they then expand or belly out a little, 

 and again grow smaller towards their outer or uterine end, which is in 

 by far the greater number of them an open mouth, when separated from 

 the uterus ; how it may be while they are adherent. Dr. Montgomery 

 does not decide. Their form is circular, or very nearly so, and in size 

 they vary in diameter from nV to ^ of an inch, and are elevated to about 

 iV of an inch above the surface to which they adhere. In the way of 

 comparison he would say that they were miniature representations of 

 the suckers of the cuttle-fish . They are not confined to any one part of the 

 decidua, and the author thinks they are usually most numerous and 

 most distinct in those parts of it which are apart from the situation of 

 the rudiments of the placenta, and at the period of gestation which 

 precedes the formation of the latter (the placenta) as a distinct organ ; 

 hence the best time for examining them is up to the third month : in 

 the advanced periods of gestation they are not to be found, at least Dr. 

 Montgomery has not seen them then. The author obsen'es further : 



" I am ready to confess at once that I am not prepared to offer any 

 very decided opinion as to the precise nature or use of these decidual 

 cotyledons, for to that name their form as well as their situation appear 

 strictly to entitle them ; but, from having on more than one occasion 

 observed within their cavity a milky or chylous fluid, I am disposed to 

 consider them reservoh's for nutrient fluids, separated from the maternal 

 blood, to be thence absorbed for the support and development of the 

 ovum. This view appears strengthened when we consider, that at the 

 early periods of gestation the ovum draws all its support by imbibition 

 and by means of the connexion existing between the decidua and the 

 villous processes on the surface of the chorion." 



An Account of Human Twin Foetuses, one of which was devoid of Brain, 

 Heart, Lungs, and Liver ; with Observations on the Nature and Cause 

 of the Circulation in such Monsters. By John Houston, M.D., 

 M.R.I.A., SfC, Dublin. 



Dr. Houston's observations were principally directed to the circu- 

 lating system in the monster, though he described in full the various 

 anomalous conditions of other organs in its body. 



The placenta was double, with separate membranes and chords for 

 each foetus : the placenta of the imperfect infant was considerably 

 smaller than that of the perfect one. The points of attachment of the 

 two chords were several inches asunder. 



The umbilical vein arising from the smaller placenta passed through 

 the umbilicus, and opened into the vena cava abdominalis, the branches 



