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epithelium having the character of the penisectoderm. In the section 
from which fig. 2g has been borrowed, the two components which 
are ontogenetically contained in it, are no more to be recognized. 
I cannot omit directing attention in this figure to the epithelial knob 
lying dorsally with respect to the urethra. It represents the “Anlage” of 
one of the so-called para-urethralpassages and is to be considered as 
a separated part of the phallus-frame or as a cell-cord grown inside 
from this frame. 
Finally I give in fig. 4 a series of sections through the urethra 
of an embryo 13cm. long (+ at the end of the 5" month) in which 
embryo the state of the full-grown man has been reached. 
The urethra mouths at the end of the penis with a vertical aper- 
ture. Where the urethra is vertical, accordingly before the fossa 
navicularis, its wall, as is shown in fig. 4a, consists principally of 
the epithelium of the phallus-frame; only an exceedingly small part 
proceeds from the penisectoderm, resp. the sexual folds. The lamellae 
of the phallus-frame are almost entirely separated, not because they 
are deviated, but because the central mass has disappeared. 
In the direction to the fossa navicularis also here the composition 
of the wall changes and the part proceeding from the phallus-frame 
becomes smaller, the part originating from the sexual folds becomes 
larger. In fig. 4c the vertical part of the canal certainly answers to 
the phallus-frame, the rest is for the greater part a production of 
the sexual folds. Also in this preparation the difference between the 
two kinds of epithelium disappears in the sphere of the fossa navi- 
cularis; in the sections from which fig. 4d-g has been borrowed the 
boundaries between the two components are no more to be seen. 
In different places separated cell-cords and tubes are present which 
must be considered as the ‘“Anlages” of paraurethralpassages; the 
tube in fig. 4f marked s.g. is the “Anlage” of the sinus of Guérin. 
The series fig. 4, like fig. 2, shows the cause of the change in 
the position of the urethra, which, as is well-known, stands vertical 
before the fossa navicularis, behind it mostly horizontal. The diffe- 
rence is based upon the difference in composition. For before the 
fossa navicularis it is the phallus-frame, which has a vertical position, 
that forms the greatest part in the wall-formation of the urethra, 
only a small part proceeds from the sexual folds. Behind this fossa, 
on the other hand, the wall of the urethra is for the greater part 
the production of the united sexual folds, only a small part proceeding 
ontogenetically from the phallus-frame. The deviation of the two 
lamellae of the phallus-frame is in this transformation an important 
factor. 
