158 JOHN SUNDWALL 



may assume the staining characteristics of elastic fibres. This 

 is especially true of the Unna-Taenzer orcein method which 

 stains elastic fibres brown. It was my practice to place the 

 sections from the stain in 70 per cent alcohol and then decolorize 

 under the microscope with acid alcohol until the section became 

 for the most part colorless. The characteristic elastic fibres of 

 the blood vessels remain deeply stained and serve as controls 

 for the degree of decolorization. In the use of Weigert's it is 

 also necessary to decolorize in alcohol until the section becomes 

 yellowish or light gray. The elastic fibres alone should be stained 

 black. 



With 'the proper degree of differentiation, using the elastic 

 fibres of arterial wall as the criterion, it will be found that elastic 

 fibres are present, as described, in the capsule; to a less degree 

 in the interlobular septa surrounding the blood vessels; and in the 

 basement membrane of the main, primary, interlobular, and 

 larger intralobular ducts. Only occasionally are they seen in 

 the walls of the small intralobular ducts. They are not present 

 as forming the walls of the acini except in rare instances, and 

 then when lobules are in contact with capsule. 



Peritubular connective tissue, 'Korbzellen\ basement membrane 



The finer structural tissue surrounding the terminal tubules or 

 acini of glands in general is composed of several elements such as 

 fixed connective tissue cells, the so called 'Korbzellen' or basket 

 cells, and the basement membrane. Much confusion exists in 

 the literature respecting the terms used to designate these vari- 

 ous tissues. Some refer to all these elements as the basement 

 membrane. Shafer ('12) states: 



In most glands the secreting cells of the alveoli and also the cells 

 which line the ducts are bounded. . . by a thin membrane, which 

 is sometimes continuous, sometimes interrupted, and which has nuclei 

 here and there scattered upon it. This is the basement membrane 

 and as the presence of nuclei indicates, it is composed of more or less 

 fused flattened cells of connective tissue nature which are sometimes 

 united edge to edge, sometimes connected only by branch processes 

 so as to form a sort of flattened basket-work around the alveoli. Even 



