REPRODUCTION. "9 
ily 
jis 
Fie. 87.—Embryo of dog, twenty-five days old, opened on the ventral side. Chest and ven- 
tral walls have been removed. a, nose-pits; b, eyes; c, under-jaw (first gill-arch); d, 
second gill-arch ; e. f g, h, heart (e, right, ‘e left auricle; g, right, h, left ventricle) ; 7, 
aorta (origin of); kk, liver (in the middle between the two lobes is the cut yelk-vein) ; 
1, stomach ; m, intestine ; n, yelk-sac ; 0, primitive kidneys: p, allantois ; ft ‘ore-limbs 5 
be ping ae The crooked embryo has been stretched straight.’ (Haeckel, after 
‘ischoff.) 
Fig. 88.—Diagram of an embryo showing the relations of the vascular allantois to the villi of 
the chorion (Cadiat). e, embryo lying in the cavity of the amnion ; ys, yelk-sac ; al, al- 
lantois ; A. V, allantoic vessels dipping into the villi of the chorion ; ch, chorion. 
