12 Normentafeln zur Entwicklungsgeschichte der Wirbelthiere. 
considerably elevated. The tail projects directly ventrad. The external nares and mouth face in the 
main caudad. The snout is quite prominent. The lids meet, closing the eye. The head and trunk are 
well covered with hair anlagen. The palm faces caudad, the sole faces in part caudad in part mesad. 
On both manus and pes the beginnings of the claws are indicated. Three separate mammary anlagen 
are visible on lateral view. The umbilicus is relatively small. Compare, for internal development, 
Table No. 24. 
There are only a few noticeable changes in this 20-day embryo as compared with that of 18 days, 
these are as follows: the snout projects a little more; the bend at the brow is a little straightened; the 
head is a little more elevated; the eyes are closed; the sole faces a little caudad. 
