BM 



Fig. 6. Two cells of the thick, a.-<cencliiig liinh ul llenle's luo\> ivstiiig on the basement membrane 

 (BM) and joined by a terminal bar (TB). The cell boundary is indicated by the dotted line. The nucleus 

 (N) is located in the apical part of the cell with the Golgi zone (Go) close to it. Extending into the 

 tubular lumen (Lu) are numerous microvilli (Vi). The cytoplasm is finely granulated because of the 

 presence of abundant RNA particles. The autofluorescent vacuoles (V) are less numerous than in the 

 proximal convolution. The mitochondria (Ml) are long and densely packed. Sometimes, their shape is 

 more like an ice cream bar than that of a sausage, which can be seen when they are sectioned at an 

 angle (M2). The basal cell membrane is deeply infolded and the turning points clearly seen at the arrows 

 show that cytoplasmic lamellae, also containing mitochondria, are always interposed in an interdigitat- 

 ing fashion. Magnification 11,000X. 



171 



