404 



JOHN LEWIS BREMER 



bules enter the duct on its dorsal aspect, some on its ventral. In 

 the chick the tubules are not so long nor so convoluted as in the pig. 

 In man also the tubules seem to be of two more or less distinct 

 groups, one entering the mesonephric duct on the ventral, one 

 on the dorsal side, and these two groups run with few convolu- 

 tions along the ventral and dorsal borders of the gland respectively 

 to the glomeruli, which lie far dorsally. The tubules of the ven- 

 tral set thus approach nearer to the genital anlage than their 

 respective glomeruli, but this is not true of the dorsal set of tu- 

 bules. None of the tubules in man ever attain the extreme length 

 found in pig, sheep, rabbit, and other animals which retain func- 

 tioning Wolffian bodies to an advanced embryonic age. MacCal- 

 lum found the full formation of the Wolffian body in the pig at 

 between 40 mm. and 95 mm., while in man he noted a reduction 

 of the number of tubules after 12 mm. This latter statement, 

 however, I cannot reconcile with what I have found in the embryos 

 of man in the Harvard Embryoligical Collection, unless very wide 

 individual differences occur. MacCallum counted 27 tubules in 

 one Wolffian body in a human embryo of 12 mm., 20 in one of 14 

 mm., and 9 in one of 20 mm. ; while, as the following table shows, 

 I have found no constant reduction in the number of tubules up 

 to 44 mm. 



Number oj tubules in one Wolffian body 



