252 VERA KOEHRING. 



The lining of the whole system of tubules is of most delicate 

 columnar epithelium which extends into the cloaca in the region 

 around the mouth of the central tubule. It is a markedly 

 different tissue from the mucous lining of the cloaca. There is 

 no mucous secretion from the spermatheca; nor at times is 

 there any secretion of any kind as far as can be ascertained by 

 staining reactions. Save for the spermatozoa during the breeding 

 season the lumina may be clean and clear. Some series, however, 

 show a faint indefinite substance, rather stringy, in the flask ends. 

 The necks and central tubule may show slight traces of the 

 matter also, though it is rare in the central tubule which is 

 generally unusually clear. 



There is a slight differentiation in the lining tissue in different 

 parts of the system. In the blind ends the cells are long. The 

 bases are densely granular with large nuclei. The apices stain 

 faintly; they seem filled with minute, transparent globules. The 

 apices are irregular they do not form an even border for the 

 lumen. They gi\ T e a picket-fence appearance. In some series 

 these inner halves of the cells are shrunken so that their ends 

 appear as amceba-like processes, or as if they were in an exhausted 

 state. Yet these conditions occur during the fall and winter 

 months during which it is to be supposed that there is no reason 

 for activity of the cells as no spermatozoa are present. 



The cells of the necks of the flask tubules are shorter than 

 those of the blnid ends and produce a much more even border- 

 that is, there is no appearance of shrinkage of the cells. The 

 apices are rounding. It is in the central tubule, however, from 

 the region of the convergence of the necks to the area surrounding 

 the mouth of the cloaca that there is the most marked difference 

 from the lining of the flask ends. The appearance of the central 

 duct is constant at all seasons. These cells do not differ as to 

 bases but the apices are very slightly longer and stain even 

 more delicately than do those of the flask ends there is no 

 globular appearance. The apices fit perfectly together and form 

 a smooth, even surface for the lumen. No variation of this 

 condition has been noted in any mature spermatheca. 



The size of the lumen of the central tubule varies it is a 

 reservoir at the convergence of the necks. In what are presumed 



