DEVELOPMENT OF THE KIDNEY. 



the renal columns [of Bertini], one of which is shown in Fig. 281. The 

 outgrowing collecting tubules derived from the pelvis do not stop at the 

 base of the pyramid but continue in tapering cones through the cortex 



FIG. 283. A SERIES OF MODELS SHOWING SUCCESSIVE STAGES IN THE DEVELOPMENT OF A URINIF- 



EROUS TUBULE, INCLUDING THE ASSOCIATED POPTION OF THE COLLECTING TUBULE. 

 From a human embryo of the seventh month. X 160. (Huber. Am. Jour, of Anat., Suppl. to vol. iv.) 



almost to its surface. They constitute an essential part of its radiate 

 portion (pars radiata] [medullary rays, pyramids of Ferreinj. 



Thus far the development of the outgrowth of the Wolffian duct 

 has been considered. The dense mesenchyma which surrounds the pelvis 



