96 



ZOOLOGY FOR MEDICAL STUDENTS 



CHAP. 



near the upper end of the blastostyle, are seen to be developing into 

 something very different from a hydroid polyp. Eventually the fully 



Fio. 37. 



Obelia. Medusa seen from below. X 30. The lower figure represents a small portion of the 

 margin of the umbrella more highly magnified, g. Gonad ; w, manubrium with mouth ; ol, otolith ; 

 olf otocyst ; r, ring canal ; r.c, radial canal ; s» stomach. 



developed bud breaks off, makes its way to the exterior through the 

 opening at the top of the gonotheca, and is now seen to be not a hydroid 



