28 



THÉEL, HERMAPHRODISM IN HOLOTHURIDS. 



Transverse sections across an immature male tube. /, longitadinal folds; 

 s, spermoblasts in the glens between the folds. Magnified. 





^ *^%\ m\ m 





vÄ^^Mff '4l^ ¥^^ Ä^ 



Transverse section of a male tube in a more advanced developmental state. 

 /, longitudinal folds; s, spermoblasts; sp, spermatozoa. Magnified. 



