No: 2,] 
’°87. WEISMANN und IscHIKAWA. 
perchen bei thierischen Eiern, 
Freiburg. 
MICRODEUTOPUS GRYLLOTALPA COSTA. 331 
1887. 
Ueber die Bildung der Richtungskér- 
Ber. der Nat. Gesell. 
Bad:in. 
‘92. WELDON, W. F. R. The Formation of the Germ Layers in Crangon 
vulgaris. 
Quar. Journ. Micr. Sci. 
Vol. xxxiii, 
1892. 
LETTERING USED THROUGHOUT THE PLATES. 
abdomen. en.inv. 
abdominal fold. Vb. 
antennae. 1a. 
appendage. m. 
blastocoel. ppl. 
cephalothorax. 
dorsal cell. pr. 
dorsal organ. st. 
ectoderm, x and y. 
entoderm. Ve 
entodermal invagination. 
liver tube. 
last appendage. 
mesoderm. 
protoplasm of cells at the 
edge of the ventral plate. 
proctodaeum. 
stomodaeum. 
degenerating cells. 
yolk area. 
