SEX-CELLS OF AMIA AND LEPIDOSTEUS 29 
mesoderm. As pointed out in my article, the lateral plates of 
mesoderm, examined immediately before their approximation in 
the median line, show no cells which, as regards size or yolk con- 
tent, in the least compare with the sex-cells. 
It is especially gratifying to me to find support for my views 
in two recent papers. In one of these Kuschakewitsch (’08), 
referring to my paper of a few months before, stated: ‘‘Der Ver- 
fasser hat die Abschnitiring von Dotterzellen lings der dorsalene 
Sagittallinie des Dottersackes im hinteren Teile des Rumpfes 
beobachtet und die Theilname dieser Dotterzellen am Aufbau 
einer kompakten Mesenterial-anlage festgestellt, die Bouin 
(1900)) als “‘ebauche génitale primordiale’”’ aufgefasst hatte. 
Wie aus meiner Schilderung der entsprechenden Vorginge in 
der Normalreihe von Rana esculenta zu ersehen ist, kann ich die 
Angaben von Allen vollstandig bestitigen.”’ 
Another paper, appearing the same year (King, ’08), gives an 
account of the origin of the sex-cells in Bufo lentiginosus which 
is In complete accord with the above, and states: ‘‘Allen’s recent 
account of the origin of the sex-cells in Rana pipiens agrees 
essentially with what I have found in Bufo.” Miss King finds 
no evidence in the course of development of any transformation 
of peritoneal cells into sex-cells as asserted by several writers 
among whom may be mentioned Bouin and Dustin. This is 
quite in accord with my observations upon Chrysemys (’06) in 
which the sex-cells were traced to the period of sexual maturity 
without finding any evidence of such transformation. 
Miss May Jarvis (’08) in a paper upon ‘‘The Segregation of the 
Germ-Cells of Phrynosoma cornutum”’ (preliminary note) finds 
the sex-cells to take their origin in the entoderm of the vascular 
area on all sides of the embryo, even cranial to it, and notes a 
few in the region of the brain. Her results are in their main 
features confirmatory of my own work upon Chrysemys. The 
following quotation from her paper is self-explanatory: ‘‘Through 
the courtesy of Dr. Allen, I have been enabled to examine the 
more important stages in the migration of the germ-cells of 
Chrysemys; they are similar to my own material, as my conclu- 
