THE MULLERIAN DUCT. 



691 



first; this is the Mullerian duct. This duct is developed from 

 before backwards. 



According as the embryo is a male or a female, so one or other 

 of these ducts develops. In the male the Wolffian duct remains 



FIG. 278. 



Transverse section through the lumbar region of an embryo chick at the 

 end of the fourth day. (Foster and Balfour.) W.R. Wolffian ridge, g.e. 

 Germinal epithelium. A.O. Dorsal aorta. M. Mesentery. SP. Splanch- 

 nopleure. d. Alimentary canal. V. Vessels, m.p. Commencing Mul- 

 lerian duct. So. Somatopleure. W.b. Wolffian body. W.d. Wolffian 

 duct. V.c.a. Posterior cardinal vein. c.h. Notochord. A, W.C. Anterior 

 white column of spinal cord. a.r. Anterior root. A.G.C. Anterior gray 

 column, p.r. Posterior root. m.p. Muscle plate, we. Canal of spinal cord. 



as the vas defereus, and the Mullerian duct becomes atrophied. 

 In the female, on the other hand, the Mullerian duct forms the 



