GERM CELLS IN PEDICELLINA AMRRICANA 



17 



head (which is itself compound), and a long whip-like tail. The 

 latter is about three times as long as the head and becomes 

 continually narrower as it runs to its end (Fig. 6i). 



IV. Oogenesis. 



A median longitudinal section of a fairly large female polyp 

 often shows, in some one view, the completely developed ovary 

 with all the stages of egg development, through the oogonia 

 and the growing oocytes to the maturing ova (Text-fig. II). 

 This structure, situated in the space between the so-called 



06/ 



/.r/l: 



V. 



l.C 



Text-fig. 1L 

 Longitudinal section of ovary showing the various shapes in development of egg. 

 od, oviduct; oog., oogonia, oocy., oocytes; li.c, liver-cells. 



" liver-cells " below, and the floor of the atrium above, is like 

 the testis, bilaterally symmetrical, each half being a pear-shaped 

 organ, the narrow end of which is at the center of the polyp in 

 connection with the oviduct, and widening as it extends outward 

 to the side of the body. In view of Ehlers', '90, comprehensive 

 description of this organ, it is unnecessary here to go into further 

 details of structure, except to note that as the full grown eggs 

 near the periphery become matured, they move back toward the 



