SEX-CORDS AND SPERMATOGONIA IN CHICK 



393 



tween the seminiferous cords; two days later there had been some 

 increase in the connective tissue, especially in the region under 

 the germinal epithelium, but in these embryos of 13 days de- 

 velopment the area of the mesenchyme far exceeds that of the 



p r. 0. 





Fig. 1 Portion of a transverse section through the left testis of an 11 day 

 chick embryo. This section shows the seminiferous cords, composed of perito- 

 neal cells and containing several primordial germ-cells. The cords are sepa- 

 rated from one another by a mesenchyme-like connective tissue. 



The figures illustrating this article Avere drawn by Mr. A. B. Streedain. Zeiss 

 apochromatic objective 1.5 mm., and compensating ocular 6 were employed for 

 all the figures. The camei-a lucida was used in making all the drawings and 

 magnification calculated at table level in all cases. The figures were reduced by 

 one-fourth in reproduction giving a magnification of 1125 diameters for all the 

 illustrations. The figures were drawn from preparations fixed in Bensley's 

 acetic-osmic bichromate mixture and stained with Bensley's anilin acid fuchsia 

 — Wright's blood stain. All the sections were cut 4 n in thickness. 



.ABBREVIATIONS 



int.C, interstitial cells 



L., lumen of seminiferous cord 



M.C., mitochondrial crescent 



p.c, peritoneal cell 



pr.o.. primordial germ-cell 



-pr'.o'., primordial germ-cell in mitosis. 



S., cell of support 



S.C., seminiferous cord 



Sp., spermatogonium 



Sp'., spermatogonium in mitosis 



Sir., stroma 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 20, NO. 3 



