173 DR. E. KLEIN. 



cess of self-digestion commonly used in the study of the pancreas- 

 ferment, i.e. the trypsin (Heidenhain^ 1. c, Poster and Langley, 

 'Practical Physiology^), but I liave not obtained any decisive 

 results. 



In another series of experiments I have prepared a glycerin 

 extract of the gland after the same manner as used in the case of 

 trypsin, and have exposed in it, diluted with carbonate of sodium 

 (l.p.c.) at 35 — 40 ceutigrades, pieces of fibrin, but have not ob- 

 tained any decisive results. When, however, diluting the gly- 

 cerin extract of the gland with 1 pro mille hydrochloric acid, 

 the fibrin, after having swollen up, broke up into tiny fragments 

 in a similar manner as is the case in pancreas digestion. On the 

 whole, then, it seems doubtful whether the submaxillary contains 

 trypsin, but this question would require for its definitive settle- 

 ment more extended observations than I have been able to devote 

 to it. 



The great mass of the alveoli of the submaxillary of man are 

 albuminous, of the same structure as in the rabbit ; in some 

 glands there are more, in others less numerous alveoli, which 

 are lined with mucous cells. But in no gland do they form more 

 than an insignificant section. The mucous cells are typical, and 

 are the same as in other mucous glands (see below). Such 

 alveoli are in direct continuation with the alveoli lined only with 

 albuminous cells. As I have pointed out in a previous paper 

 ('Quarterly Journal of Micr. Science,' April 1879), the alveoli 

 lined with mucous cells are larger, and their lumen is larger than 

 those lined with albuminous cells. That these mucous alveoli 

 are directly continuous with the albuminous alveoli, of this I am 

 fully convinced, as also of the fact that where a mucous alveolus 

 is viewed more or less obliquely just at the point of its transition 

 into an albuminous one, the appearance is produced as if at the 

 cut end there were albuminous cells placed outside the mucous 

 cells, and as if forming here a cresceutic group similar to the 

 crescents in the submaxillary of the dog. But the two are totally 

 different from one another, for in the former the apparent cres- 

 cents of albuminous cells are in reality the cells lining the lumen 

 of the albuminous portion of the alveolus, continuous with the 

 mucous portion. 



In one of the two apes that I have examined on this point, I 

 found only in the submaxillary of one indications of mucous 

 alveoli ; they were present in very small numbers amongst the 

 great mass of albuminous alveoli, and the two were also here 

 continuous with another. 



