639 
apparaissant des expansions protoplasmiques (b, e, f, c) sous la ferme 
d’ épines raides, 4 peine perceptibles. 
On peut voir, également, qu’ a cette époque les racines posté- 
rieures sont en grande partie formées (B) ainsi que les antérieures (A), 
sur lesquelles il n’ est pas rare de trouver quelque cylindre-axe en 
voie de développement (h, 2). 
En resumé: Chaque cellule nerveuse passe par 3 phases successives : 
1) Phase épithéliale ou bipolaire, durant laquelle la cellule 
conserve encore une position convergente entre les spongiobiastes et 
une expansion épendymale ou interne (fig. 7°a). 2) Phase uni- 
polaire (névroblaste de His) qui survient en conséquence de I atro- 
phie plus ou moins complete de |’ expansion épendymale (f, ce). Souvent, 
cette phase fait défaut, devenant |’ expansion interne le premier appen- 
dice protoplasmique. 3) Phase multipolaire, arrivant par suite 
des projections protoplasmiques du corps cellulaire et de la portion 
plus immédiate des expansions primordiales. 
23. Aoüt 1890. 
Nachdruck verboten. 
On the Fate of the Human Decidua reflexa. 
By CHarLes Sepewick Minor. 
With 1 Figure. 
(Abstract.) 
The decidua is a distinct membrane up to the end it is said of 
the fifth month of gestation, and after that period it can no longer 
be found. Exactly at what time it disappears is not established 
by observation though the fact of the disappearance has long been 
known. Nor have we had hitherto any definite knowledge as to how 
it disappears, although its gradual attenuation and increasing trans- 
parency during the first four or five months have been familiar to us 
since the publication of Cosre’s magnificent atlas. The view most ge- 
nerally accepted has been that it fused with the decidua vera and 
that accordingly the layer of decidua nearest the chorion during the 
latter half of pregnancy represents the decidua reflexa. 
I have had opportunity to study four well preserved normal preg- 
nant uteri of two, three, five to six, and seven months gestation re- 
spectively. These show that at two months the decidua reflexa is 
45 * 
