Figure 2. Model of testis cord formation. The average morphometric values of testis development described by Nel-Themaat et al (2009) were used to generate three-dimensional models of the Sertoli cell–germ cell mass and testicular cords at different stages of development. Gonad borders indicated by dashed lines. Scale bar = 300 µm. The embryonic day 13.5 gonad is the still image for the Supplemental Figure 2 movie.