GEEM-CELL HISTORY IN THE BROOK LAMPREY 



127 



Young, Robert T., and Leon J. Cole 1900 On the nesting habits of the brook 

 lamprey (Lampetra wilderi). Amer. Nat., vol. 34. 



Zarnik, B. 1911 Ueber den Chromosomenzyclus bei Pteropoden. Verb. 

 deutsch. zool. Ges., Vers. 20-21, 



PLATES 



ABBREVIATIONS 



arc, archenteron 



ast., astrosphere 



bv., blood-vessel 



c, centrosome 



ch., chromidia 



CO., coelom 



cy., cyst 



d.a., dorsal aorta 



deg.cy.L, degenerating cyst, early stage 



deg.cy.2. , degenerating cyst, late stage 



d.g., dividing germ cell 



deg.g., degenerating germ cell, early 



stage 

 ex., extruded germ cell 

 ex.cy., extraregionary cyst 

 f.c, follicle cell 

 g., germ cell 

 g.c.r., germ cell region 

 (I.e., germinal epithelium 

 g. J., germ cell fragment 



gon., gonad 



i.e., intestinal epithelium 



lu.i., lumen of intestine 



m., mitochondria 



m.h., midbody 



TO.c, mesenchyme cell 



mes., mesoderm 



mesn., mesonephros 



m.f.c., migrating follicle cells 



n., nucleus 



nch., notochord 



n.t., nerve tube 



o., oocyte 



p.c.v., postcardinal vein 



pr.d., pronephric duct 



St., stroma 



t., tetrad 



v., vitelline body 



w.f., wolffian duct 



y., yolk 



All outlines were made with a camera lucida. 



JOURNAL OF MORPHOLOGY, VOL. 35, NO. 1 



