322 Granule Cells of Paneth in Intestinal Glands of Mammals 
holding cells, others in the cylindrical cells. I have not been able to assure 
myself definitely of the occurrence of mitoses in the cells of Paneth. The 
small size of these cells and their more irregular shape and arrangement 
make the exact determination of the nature of the mitotic cells somewhat 
difficult. 
The distribution of the cells of Paneth in the intestinal epithelium 
of the opossum, the occurrence of the fully loaded cells in the surface 
epithelium and of immature cells in the gland cannot be reconciled in 
any way with Bizzozero’s view that they are young cells which only achieve 
their full development as mucus-secreting goblet cells, nor, indeed, with 
any view except that they are specific elements engaged in the production 
of a special secretion. 
The material from the guinea pig proved the most fruitful in results 
as regards the cytological characters of the cells of Paneth and in this 
animal results were obtained which bring the cells of Paneth into lne 
with other sero-zymogenic cells such as the cells of the parotid gland, 
the chief ‘cells of the fundus glands and the pancreatic cell. 
At first, considerable difficulty was experienced in obtaining accurate 
fixation of the granules. Aqueous sublimate, Bensley’s alcohol-bi- 
chromate-bichloride mixture, and Kopsch’s formaline bichromate mix- 
ture, were tried with only partial success. A few of the cells at the 
very edge of the section, in these imperfect fixations, would be found to 
have retained the granules while from the majority of the cells they had 
either been removed entirely or only retained in an imperfect and dis- 
torted form. Very frequent in these cases were the crescent-shaped 
granules described by Nicolas in the Paneth cells as one of the stages in 
the secretory history of the cells. A great deal of the work was done on 
material fixed in 10 per cent formaldehyde which penetrated somewhat 
better than the other fluids mentioned above, although in this fixing 
fluid the crescentic-shaped granule was common. When the work was 
nearly completed we succeeded in obtaining complete fixation of the 
granules by means of a combination of equal parts of alcoholic sublimate 
and Kopsch’s fluid. In preparations fixed in this mixture the granules 
retained their round form and were perfectly fixed in all the cells of the 
material. 
For staining, Bensley’s neutral gentian was employed with good success 
to differentiate Paneth cells, the granules of which stained intensely 
violet, from goblet cells which remain colorless or faintly violet. Another 
method which has rendered great service is staining in iron haematoxylin 
followed by mucicarmine. By this method the granules of the Paneth 
cells are stained deep blue-black, those of the goblet cells carmine red. 
