122 



THE DEVELOPMENT OF THE GAMETES OR SEX CELLS 



Species 



Place of Origin, etc. 



Author 



Lophius piscatoriiis 



Germ cells segregate from primitive 

 entoderm; migrate through meso- 

 derm to site of gonad; migration 

 part passive and part active 



Dodds. 1910. 

 J. Morphol. 21 



Fundulus Germ cells segregate from peripheral 



heteroclitiis entoderm lateral to posterior half 



of body; migrate through ento- 

 derm and mesoderm to the site 

 of the developing gonad 



Cottiis hairdii Primordial germ cells derive from 



giant cells, in the primitive ento- 

 derm; migrate through the lateral 

 mesoderm into the site of the de- 

 veloping gonad 



Lebistes reticulatus 

 (guppy) 



Germ cells segregate early in devel- 

 opment; first seen in the entoderm- 

 mesoderm area; migrate into the 

 sites of the developing ovary and 

 testis, giving origin to the defini- 

 tive germ cells 



Richards and Thomp- 

 son. 1921. 

 Biol. Bull. 40 



Hann. 1927. 

 J. Morphol. 43 



Goodrich, Dee, Flynn, 



and Mercer. 1939. 

 Biol. Bull. 67 



Rana temporaria Germ cells segregate from primitive 



entoderm; migrate into developing 

 genital glands 



Rana temporaria Primordial germ cells from ento- 



derm discharged at first spawning. 

 Later, the definitive germs cells of 

 adults originate from peritoneal 

 cells 



Witschi. 1914. 



Arch. f. mikr. Anat. 85 



Gatenby. 1916. 

 Quart. J. Micr. Sc. 61 



Rana catesbiana Primordial germ cells segregate 



from primitive entoderm; defini- 

 tive germ cell derives from pri- 

 mordial cells according to author's 

 view but admits possibility of ger- 

 minal epithelium origin 



Rana temporaria, 

 Triton alpestris, 

 Bufo vulgaris 



Primordial germ cells segregate from 

 entoderm 



Swingle. 1921. 

 J. Exper. Zool. 32 



Bounoure. 1924. 

 Compt. rend. Acad. d. 

 Sc. 178, 179 



Rana sylvatica Primordial germ cells originate from 



entoderm and migrate into the de- 

 veloping gonads. They give origin 

 to the definitive sex cells 



Witschi. 1929. 

 J. Exper. Zool. 52 



Hemidactylium Primordial germ cells arise in meso- 



scutatum derm between somite and lateral 



plate; move to site of gonad by 

 shifting of tissues 



Humphrey. 1925. 

 J. Morphol. 41 



