342 RANDOLPH. 



EXPLANATION OF PLATE III. 



LUMBRICULUS VARIEGATUS GrUBE. 



Fig. io. From a transverse section through a more advanced stage than in Fig. 9. 

 The median ccelomic spaces have united and more cavities appear in the lateral 

 mesodermic elements. The neural foundations have united in the median line and 

 nerve fibres have developed. X 490. 



Fig. io«. A less highly magnified view of the section shown in Fig, 10. X 250. 



Fig. 1 1 . From a section of the same series as in Figs. 7, 8, 9, sixty-five sections 

 anterior to the one figured in 9. The dorsal wall of the median ccelomic cavity has 

 grown down into the cavity and the sides of the loop thus formed have united above, 

 making a tube which is the ventral longitudinal blood vessel. The neural cord with 

 cells and fibres is now well developed. X 600. 



Fig. 12. From a transverse section of a stage more advanced than that in Fig. 11. 

 The tissues and the ccelomic cavity have nearly reached the adult condition. A 

 neoblast in characteristic position shows the nucleus and cell body. X 600. 



Fig. I2a. From the section next to that in Fig. 12, showing the nucleolus of the 

 neoblast in Fig. 12, and the connection of the setigerous gland with the ectoderm. 

 X 520. 



All the figures were drawn with camera. 



