GERM-CELL HISTORY IN THE BROOK LAMPREY 



31 



RESULTS AND CONCLUSIONS 



c. Review of work on the early history of the germ cells in 

 lampreys. W. MuUer (75) described the germ glands of young 

 lamprey larvae as median, unpaired thickenings of the perito- 

 neum situated between the bases of the mesonephric bodies 

 and extending along the whole length of the body cavity. At this 

 stage groups of germ cells were found, but sex could hot be 

 distinguished. 



Goette ('90) found the reproductive cells in larvae of a much 

 earlier stage, corresponding approximately to that represented 

 by my figure 7. He observed that, while most of the cells in the 

 mesodermal plates soon lost their yolk and began to divide, 

 some of the cells retained their yolk and remained undivided. 

 These cells were found in the mesodermal plates on both sides 

 along their thickened median portions directly under or outside 

 of the pronephric ducts and sometimes against the yolk entoderm, 



JOCRNAL OF MORPHOLOGY, VOL. 35, NO. 1 



