Waite. — Autennal Glauds. 



PLATE 3. 



(Dorsal is up on the plate in all figures. In Figs. 26, 27, 28, 30, anterior is to the 

 right; in Figs. 21), 31, median is to the right. Mesoderm is distinguished by the 

 darker shade.) 



Fig. 26. Lateral face of a parasagittal section through left antenna of embryo, 

 showing vacuolation in the endsac and the path of the ectodermic 

 invagination. The invaginated cells in Figs. 26, 27, are more deeply 

 shaded than the rest of the ectoderm. X 410. 



Fig. 27. Similar section in slightly older embryo, showing expansion at deep 

 end of ectodermic invagination, and a lumen formed in the endsac. 

 X 410. 



Fig. 28. Similar section in embryo about 35 days old, showing position of future 

 lumeu of ectodermic sac. X 410. 



Fig. 29. Anterior face of transverse section through right antenna of an embryo 

 about 40 days old, showing lumina of endsac and ectodermic sac and 

 duct to exterior. X 410. 



Fig. 30. Lateral face of a parasagittal section through left antenna of embryo 60-70 

 days old, showing growth of ectodermic invagination around the end- 

 sac. X 410. 



Fig. 31. Anterior face of transverse section through right antenna of embryo 3 to 4 

 months old, showing extension of ectodermic invagination. X 410. 



