MAMMALIA. 483 
Fig. 330.—ANn EmBryo Horse oF SIx WEEKS IN ITs MEMBRANES. 
(After Ewart.) 
tied eee 
hiotowte 
va 
‘Note the reduced yolk-sac (y.s.), the enormously distended allantois (ad/.) forming a diffuse 
placenta, the prokalymma (a.c.), and the villi of the serosa (#.g.). “The amnion (a#.) is black. 
Fic. 331.—S1x DIFFERENT TYPES OF PLACENTA. 
E 
A, Discoidal. B, Dome-shaped. C, Zonary. D, Diffuse. E, Cotyledonary. 
F, Metadiscoidal. 
