SEGREGATION OF THE GERM-CELLS OF THE 

 TELEOST, LOPHIUSi 



GIDEON S. DODDS 

 From the Graduate School, University of Pennsylvania 



Thikty-four Figures 



CONTENTS 



Introduction 564 



I. Review of the literature 565 



1. Tiie origin of the germ-cells 565 



a. Germinal epithelium 565 



b. Gonotome theory 565 



c. Early segregation 566 



2. Migration of germ-cells 569 



a. Means of migration 569 



b. Path of migration 569 



c. "Lost" and degenerate germ-cells 569 



3. Distinctive characters of the early germ-cells 570 



II. Observations on Lophius piscatorius 571 



1. Material and methods 571 



2. Distribution and migrations 572 



3. Number of germ-cells 577 



4. Distinctive characters of the early germ-cells 579 



a. Middle period 579 



b. Later period 581 



c. Early period 581 



5. Discussion and conclusions 587 



a. Means of migration 587 



b. Path of migration 588 



c. Segmental relations 588 



d. Criteria of germ-cells 589 



e. Period of rest of the germ-cells 590 



f. Nuclear processes in germ-cell segregation 592 



6. Summary 594 



Bibliography 596 



Explanation of figures 600 



^ Thesis presented to the Faculty of the Graduate School of the University of 

 Pennsylvania in partial fulfillment of the requirements for the degree of Doctor 

 of Philosophy^ 



