420 Maine; agricultural exp]$rime;nt station. 1912. 



differentiation is to be found it must be looked for in the minute 

 histology of the glands. 



Under higher magnification it is clearly seen that the layer of 

 gland tissue is composed of tubules very similar in shape and 

 size to those seen in the earlier sections. Further search reveals 

 the openings of these gland tubules through the epithelium 

 (fig. 472). The openings of these glands appear to differ some- 

 what from those found in the anterior regions, e. g. in the albu- 

 men portion (cf. fig. 465). In the albumen region it appears 

 as if the epithelium were invaginated to meet the gland tubules 

 while in the uterus the gland cells appear to force their way 

 through the epithelium with only a slight indentation of the 

 latter. In the one case a short epithelial duct is formed, while 

 in the other, the duct, if it may be so called, is composed of 

 gland cells. I am not at all certain that any significance should 

 be attached to this point but I have observed this difference 

 very constantly in my sections. 



The chief difference in the appearance of the uterine glands 

 is in the appearance of the gland cells themselves. A com- 

 parison of figures 465 and 472 will make clear this difi'erence 

 between the albumen and uterine regions. Both figures are 

 taken from active oviducts. In the active gland from the albu- 

 men region the nucleus is small, dark staining and lies well 

 towards the proximal end of the cell. In the uterus the cell 

 nucleus is larger, more regular in shape and usually lies towards 

 the center of the cell. The chromatin granules and nucleoli take 

 on . a comparatively deep haematoxylin stain but the nucleus 

 as a whole does not show the intense stain found in the albumen 

 and isthmus regions. 



The cytoplasm in cells of the uterine tubular glands does not 

 present the heavy granular appearance described for the albu- 

 men portion. Instead these cells are diffusely granular in ap- 

 pearance. The granules are all of small size and take a rather 

 weak stain with haematoxylin. In some cells there is evidence 

 of the clumping of these granules, especially towards the peri- 

 phery of the cell. I am not sure that this is not an artifact due 

 to the fixation. 



In actively secreting glands (fig. 472) this granular material 

 can be seen lying outside the gland cells in the ducts and even in 

 the lumen of the oviduct itself. 



