G. Carl Hiiber . 37 



over and form the anlage for the uriniferous tubules, as in the develop- 

 ing kidne3'S of human embryos of from 3 cm. to 6 cm. in length the 

 neogenic zone is found, not only at the periphery of the organ, imme- 

 diately under the capsule, but forms septa which extend nearly to the 

 pelvis of the kidney and are found at the line of miion of 4 to G primary 

 lobules into which the parenchyma of the organ may at this early stage 

 of its development be separated. These septa, which Haugh has termed 

 " the primary columnte Bertini," are in realit}^ composed of the neogenic 

 zones, separated at the time when they are first recognizable and for 

 some little time after by only minimal traces of mesenchymal tissue, 

 which occurs here and there in small areas and does not present at this 

 stage of development the relatively dense structure of the capsule, which 

 dips down at the superficial boundaries of these primary lobules for a 

 variable though always short distance. Uriniferous tubules develop on 

 each side of these septa in the same way as under the capsule and it is 

 evident from a study of sections that the end branches which reach these 

 septa or primary columnaB Bertini do not meet resistance in their further 

 growth by the capsule or by a tissue of like density, since such tissue is 

 not found in the primary columnaa Bertini, when first formed and for 

 some little time after. 



In Fig. 7 is reproduced a portion of a section from a series of longi- 

 tudinal sections of a kidney obtained from a human embryo measuring 

 6.5 cm. in length (jSTo. 11), showing the junction of two primary lobules. 

 In this figure is represented a primary columna Bertini, which extends 

 from the capsule nearly to the pelvis of the kidney and the renal paren- 

 chyma developing on either side of it. As will be observed, collecting 

 tubules grow toward the septum from either side and renal vesicles and 

 tubular anlagen develop on either side of it in a manner similar to those 

 which develop under the capsule. For the greater part of its extent 

 this columna or septum contains at the stage of development shown in 

 the figure very little mesenchymal tissue. This is well developed only 

 near the pelvis of the kidney, from which it extends outward for a short 

 distance and here clearly separates the two lobules. For a fuller con- 

 sideration of the primary lobulation of the developing kidney and of 

 the primary columnae Bertini, the reader is referred to Haugh's paper, 

 who considers these questions at some length. 



Stoerk, in his second paper, discusses and figures (Figs. 3-8) wax reconstructions 

 of tubular anlagen showing the S-shape. I desire to consider somewhat more fully 

 his observations relating to this stage of the development of the uriniferous tubules, 

 as these observations are not in harmony in all particulars with my own. Stoerk in 

 this paper begins bis description of the development of the uriniferous tubules with a 

 stage, which, in profile view, presents the appearance of an inverted question mark. 

 This twisted structure simulates, as he states, in sections the appearance of an 

 S-shaped tubule and is s > recognized by authors. With reservation, he adopts the same 

 designation. In this he recognizes, for convenience of description, .3 parts (and in 



