412 



H. H. Newman and J. T. Patterson. 



ROBINSON, ARTHUR. Observations upon the development of the segmentation 



1892. cavity, the artfhenteron, the geiminal layers, and the amnion in 



mammals. Q. J. M. S., vol. 43, pp. 369-456. 

 ROSNER, M. A. Sur la genese de la grossesse gemellaire monochoriale. Bull. 



1901. Acad. Sc. de Cracovie. 

 SELENKA, EMIL. Die Blatterumkehrung im Ei der Nagethiere. Wiesbaden, 



1884. pp. 67-99. 

 SILVESTRI, FILIPPO. Contribuzioni alia conoscenza biologica degli Imenotteri 



1906. parassiti. I. Annali R. Scuola Sup. d" Agricoltura. Portici. vol. 

 6. 15 Gennaio, 1906. 



REFERENCE LETTERS 



a. a., amniotic attachment to wall of 



vesicle. 

 al., allantois. 



al.en., allantoic entoderm. 

 al.ms., allantoic mesoderm. 

 am., amnion. 

 am.c., amniotic cavity. 

 am.c.c., amniotic connecting canal. 

 a.v., aborescent villi. 

 b.b., belly-stalk bands. 

 b.c., blood cords. 

 b.s., belly-stalk. 

 b.v., blood vessel. 

 c., cervix of uterus. 

 c.a., clear area of Trager. 

 c.am.c., canal of the common amnion. 

 c.e., canal enlargement. 

 c.L, corpus luteum. 

 co. } coelome. 

 d.b., dorsal bridge. 

 d.n., dorsal notch. 

 ec., entoderm. 

 en., entoderm. 

 e.v., extra chorionic vesicle. 

 ex.c., extra embryonic body cavity. 

 f.g., fore-gut. 



f.n.t., floor of the neural tube. 

 f.t. t Fallopian tube. 

 f.u., fundus end of uterus. 

 /.., flattened villi of Trager. 

 h.f., head fold. 

 h.ms., head mesoderm. 

 h.p., head process. 

 i., infundibulum of the Fallopian tube. 



i.L, intestinal loop. 

 l.s., lymph sinus. 

 ms., mesoderm. 



ms.co., mesodermal connection. 

 m.p., medullary plate. 

 n.ch., notochord. 

 n.g., neural groove. 

 n.l.L, notch of the left lateral lobe. 

 o., ovary. 



p. am., posterior amniotic process. 

 p. am.c., posterior amniotic cavity. 

 p.p.h., protochordal plate of Hubrecht. 

 p.p., primitive pit. 

 p.r., placental ring. 

 p.s., primitive streak, 

 s., somite. 



s.am.c.c., supernumerary connecting can- 

 al of amnion. 

 s.t., sinus terminalis. 

 s.v., scale-like villi. 

 t.m.p., tip of the medullary plate. 

 tr., Trager. 

 tr.c., Trager cavity. 

 tr.e., Trager epithelium. 

 tr.k., Trager knots. 

 u.m., uterine mucosa. 

 v., villi. 

 vg., vagina. 

 y.s.j yolk-sac. 

 y.s.en., yolk-sac entoderm. 

 y.s.w., yolk-sac wall. 

 I, II, III, and IV, refer respectively to 

 the ventral, right lateral, dorsal, and 

 left lateral embryos. 



