56 
All these experiments resulted negatively, which was anticipated 
from our previous studies upon the effect of homologous blood 
serums. This 'tends to confirm the clinical observations that the 
poisons causing the toxemias of pregnancy do not come from the fetus. 
TTe then made a series of experiments upon female guinea pigs with 
placental extracts. The placenta (almost at full term) was ground up 
in a mortar and allowed to ‘^autolyze” about an hour at room tem- 
perature, and some of the resulting extract was injected subcutane- 
ously into female guinea pigs. 
After an interval of twenty-two days the guinea pigs were again 
inoculated vdth a placental extract. This time the placenta was 
allowed to ^ ^ autolyze ” three hours in the incubator (37° C.) . Five pigs 
were te*sted Avith this placental extract ; three of them were given 6 c. c. 
into the peritoneum, two of these three showing pronounced symp- 
toms of anaphylaxis. The remaining one showed slight s^miptoms. 
Six cubic centimeters of the same placental extract injected into the 
peritoneal cavity of two young normal guinea pigs as a control pro- 
duced no apparent effect. The remaining pigs were injected vdth 
small quantities of the extract intracerebrally, vuth negative results. 
These experiments were repeated vdth precisely similar results. 
Thus four more guinea pigs were sensitized ^vith different quantities of 
guinea-pig placental extract, and after a period of twenty-two days 
were given a second injection of similar placental extract. The 
extract used at both the first and second injections in these four pigs 
was autolyzed three hours in the incubator, then strained through 
gauze. All four of them showed definite symptoms. 
In a third experiment three guinea pigs were sensitized subcutane- 
ously with placental extract (three hours at 37°), and after an interval 
of twenty-four days the second injection was given directly into the 
circulation by the intracardiac method. These three pigs showed 
severe and early symptoms, including convulsions. Three normal 
control guinea pigs treated m the same manner did not respond. The 
three pigs that responded to the second intracardiac injection were 
autopsied and found to have a fresh current-jelly clot in the pericar- 
dial sac. How much this hemorrhage, which is probabH due to the 
puncture of superficial vessels of the heart, may account for the s^unp- 
toms is doubtfid. Further work along this line is in progress. 
From this limited series it is evident that the mother guinea pig 
may be sensitized vdth the autolytic products of her ovm placenta. 
These experiments naturally suggest that there may be a certain 
relation between some cases of puerperal eclampsia and the phenome- 
non in the guinea pig which we are studying. Further studies along 
this line are now being made, especially to determine whether the 
liver lesions may thus be produced in the guinea pig and other 
animals. 
