147 
occurs, the beginning of which is already visible in fig. 1 (*). 
Opposite the depression of the ectoderm a similar one is 
found in the entoderm at the nch of the anal diverticulum. 
In an egg as represented in fig. 40 c we see, at 
the bottom of the shallow invagination of the ectoderm 
mentioned above, a little pit, as yet not very deep, from 
Fig. 40. Four eggs of Kang esculenta during the closure 
of the medullary folds. 
(a) anal pit, b/ blastopore. 
which a still more shallow groove, the anal groove, runs 
forward to the blastopore-slit. The longitudinal section 
of the egg is given in fig. 3 of the plate. It bears a close 
relation to fig. 2; the anal membrane has, however, become 
thinner. 
