68 PRACTICAL HISTOLOGY. 



present which are still united in groups or patches, 

 in which, when viewed from the surface, the bases 

 of the cells have a mosaic appearance. Moreover, a 

 few "goblet" cells may here and there be met with, 

 no doubt produced in a similar manner to those 

 found amongst the columnar cells of the intestine 

 and elsewhere, viz., by a swelling up of the mucus 

 contained within the cells when these come in con- 

 tact with a watery fluid. In these cases the base of 

 the cell is ruptured and the cilia are destroyed. 



Besides the ciliated cells certain others may be 

 seen in the specimen which are of an irregular and 

 usually elongated shape, with pointed and often 

 branched extremities, and are destitute of cilia. 

 They lie, in the natural state, between the ciliated 

 cells, but their position can only be properly studied 

 in sections of the mucous membrane. 



If it be wished to permanently preserve such a 

 preparation as that now under description, it is 

 necessary first to stain the cells somewhat and then 

 to substitute glycerine for the staining fluid. Either 

 dilute logwood or one per cent, osmic acid solution 

 may be used for staining the cells. The former 

 colors their nuclei very intensely, the latter gives a 

 uniform gray tint to the cells. The coloring fluid 

 is applied in the following manner : A little is taken 

 up into a pipette and a drop is then brought in con- 

 tact with one edge of the cover-glass. The pipette 

 is then removed, and at the other edge a small piece 

 of filter-paper, torn into a triangular shape, is placed, 

 with the apex of the triangle touching the cover- 

 glass, so as to draw the fluid slowly through. When 

 the staining fluid has replaced the water in which 

 the preparation was made, the filter-paper is removed, 

 and the preparation is left until the cells appear 

 sufficiently colored, a little more fluid being occa- 

 sionally added if there seems any danger of the 

 specimen becoming dry. With a solution of log- 

 wood, even though very dilute, a few minutes 



