PLATE 2 



EXPLANATION OF FIGURES 



4 Example of a growing graft. Testis graft; embrj'o no. 17-7. Gr, graft; 

 hv, blood vessel. X 4. 



5 Section of a testis graft. Embryo no. 20-1. £"(:■, ectoderm of chorion; eo, 

 entoderm of allantois; hv, blood-vessel; va, vascular area; ga, growing area; na, 

 necrotic area. Oc. 4 X obj. 32. 



6 Portion of a growing area of the same section, magnified. St, seminiferous 

 tubules: mi. mitotic figures. Oc. 2 X obj. 1/12. 



44 



