151 
the ventral side, the distance from the animal pole to the 
slit-like blastopore measured ventrally being much less 
than 180°. In accordance with this the dorsal blastopore 
lip, as fig. 7 (plate) compared with fig. 1 (plate) shows, 
and the archenteron under it are developed strongly, the 
b. 
Fig. 41. Three eggs of bete baga tigrinum during the closure 
of the medullary fo 
a anp from behind, 5 ‘dorsally, c (the same as b) and 
d ventrally. 
a. isen bl. blastopore, h.p. cerebral plate, k, head. 
ventral blastopore lip and the so-called anal diverticulum 
very little. Yet both the latter are still quite well recognizable 
and on the outside of the ventral lip, a little distance behind 
the blastopore, may even be noted a small depression of 
