URINOGEN1TAL OEGAKS. 



297 



and only secondarily communicate with the segmental 

 duct (Fig. 23-iA to c, and Fig. 235). 



Each pronephric and mesonephric tubule is made up of the 

 following portions (see Fig. 234<A) : (1) a funnel-shaped ciliated 

 aperture, communicating with the body-cavity (peritoneal funnel, 

 nephrostome, Fig. 23-iA, ST) ; (2) a rounded mass of capillaries 



FIG. 234A. DIAGRAM OF THE (SECONDARY) CONNECTION OF THE MESONEPHIUC 

 TUBULES WITH THE SEGMENTAL DUCT (8G). 



The two anterior tubules are already connected with the duct, while the two posterior 

 have not yet reached so far. 



ST, nephrostome ; M, glomerulus ; DS, coiled glandular tubule ; ES, terminal 

 portion of latter. 



FIG. 234s. HORIZONTAL SECTION THROUGH AN EMBRYO OF Laccrta aailis 



(After M. Braun.) 



Pep, peritoneal epithelium ; Sg.bl, segmental vesicles ; Uw, mesoblastic somites. 



(glomerulus) (M\ arising from the renal artery, which lies within 

 an expanded portion of the tubule the Malpighian capsule, 

 the outer wall of which is pushed in to receive it (3) a coiled 

 glandular tubule (DS) ; and (4) a terminal portion (JSS) 

 connecting the latter with the segmental duct () fComp' 

 also Fig. 235.) 



