NOn2. |) /AZIECRODEUTOPOCS GRYELOTALPA COSTA. 329 
figures in Gammarus, or as Dr. McMurrich (95) describes for 
the isopods. 
We have seen how the liver tubes formed first in the region 
of the dorsal organ, where the greater mass of the invaginated 
cells lay; now we find the digestive tract completely formed in 
that region, whereas, anteriorly and posteriorly, it has not 
begun to form. The cells also present exactly the same ap- 
pearance as those of the liver tubes; therefore, I conclude that 
the whole digestive tract, except the short anterior and pos- 
terior portions, is formed from the invaginated cells. If cells 
from the ventral plate or from the stomodaeum or proctodaeum 
were carried in to form the digestive tract, then I should ex- 
pect to see the ends formed before the central portion. 
