A. J.P. VAN DEN BROEK, “About the development of the urogenital canal (urethra) in man.” 
Fig. 2. 
In the figures 1, 2 and 4 the phallus-frame is black, the penisectoderm marked 
with transverse lines. g. p. sexual fold. 
Proceedings Royal Acad. Amsterdam. Vol. XI 
