THE URINOGENITAL SYSTEM dsl 
this process extends over the whole of the latter period of incu- 
bation, and is completed at hatching. Parts, however, remain 
in the male in connection with the testis; non-functional remnants 
Kia. 219. — Profile reconstruction of part of the 
mesonephros and diverticulum of the ureter of 
aduck embryo of 50 somites. (After Schreiner.) 
Cl., Cloaca. Int., Intestine. Mn. T., Meso- 
nephric tubules. n. T., Nephrogenous tissue. 
Ur., Ureter. W. D.. Wolffian duct. 
XXXII, XX XIII, XXXIV, Somites of the 
same number. 
may also be detected in the female (p. 401). It is difficult to 
state the exact period of beginning and cessation of function of 
the mesonephric tubules. Judging from the histological appear- 
Fic. 218. — Profile reconstruction of part of the Wolffian duet and primordia 
of mesonephric tubules (represented by circles) of a duck embryo of 45 
somites. (After Schreiner.) 
XXIV, XX/V, ete., position of the corresponding somites. Lines 114 A, 
114 B, 114, represent the positions of the sections shown in these figures. 
