182 JOHN SUNDWALL 



juice containing 0.2 per cent of hydrochloric acid; (6) structure 

 of cells. However "It is obvious that no absolute proof of 

 the mucous character of the glands of Brunner can be brought 

 forward until a positive microchemical test for the various mucins 

 is devised." He suggests that mucous glands may contain small 

 amounts of ferment. See also Bensley's ('02) summary of 

 results in the histology of cardiac glands. 



Similarities of mucous and serous cells 



Regarding serous and mucous cells investigators agree that in 

 both types the process of secretion is very similar and that the 

 secretory substance is present in the form of very small globules 

 generally termed granules. These granules are seen in fresh 

 tissues with a few exceptions. They vary in size and in degree 

 of light refractibility. The small granules have a greater re- 

 fractive index than do the larger ones. In the case of the latter 

 this index may be very nearly the same as that of the mounting 

 medium so that they appear very dim, 'matte/ or can not be 

 seen at all — this is true also of the granules of certain cells through- 

 out their secretory activity. In the resting cell before secretion 

 has begun the cell is full of granules, and the nucleus which may 

 appear flattened or angular lies at the base of the cell. After 

 stimulation the granules are greatly decreased or disappear, the 

 nucleus becomes round or oval and approaches the center of the 

 cell. In most instances these granules can be fixed and stained. 

 Usually the smaller ones stain more intensely than do the larger. 

 In many glands the larger granules disappear in the process of 

 fixation and an intergranular protoplasm remains. 



Granules in lachrymal gland 

 According to Langley (lachrymal gland of the rabbit) — 



In the resting gland the alveoli are throughout unevenly stained. 

 The nucleus is irregular and lies in the peripheral portion of the cell. 

 During activity the outer portion of each alveolus begins to stain 

 evenly at first without much alteration in the nuclei or in the inner 

 portions of the cells, later the nuclei become larger and travel towards 



