STRUCTURE OF THE KIDNEY. 



351 



recognized. These intervening tubules, called the looped tubes 

 of Henle, arising from the straight tubes in some part of their 

 course, or being continued from their extremities at the bases 

 of the pyramids, pass down loopwise in the pyramids for a 



FIG. 122. 



FIG. 121. 



FIG. 121. A. Portion of a secreting canal from the cortical substance of the kid- 

 ney. B. The epithelium or gland-cells, more highly magnified (700 times). 



FIG. 122. Diagram of the looped uriniferous tubes and their connection with the 

 capsules of the glomeruli (from Southey, after Ludwig). In the lower part of the 

 figure one of the large branching tubes is shown opening on a papilla; in the mid- 

 dle part two of the looped small tubes are seen descending to form their loops, and 

 reascending in the medullary substance ; while in the upper or cortical part, these 

 tubes, after some enlargement, are represented as becoming convoluted and dilated 

 in the capsules of glomeruli. 



longer or shorter distance, and then, again turning up, end in 

 the convoluted tubes whose extremities are dilated into the 

 Malpighian capsules before referred to (Fig. 122). On a 

 transverse section of a pyramid (Fig. 123), these looped tubes 



