32 THE VENOM OF HELODERMA. 



Compared with the cells of the normal tubules, the cells of the gland, after 

 injection of pilocarpine, appear much shrunken. The free surface of the cells 

 also appears to be less regular, though in neither case have we been able to 

 observe a limiting membrane, the naked protoplasm appearing to be in direct 

 contact with the lumen (cf. fig. 13). 



A small amount of secretion was present in the tubules. This was similar 

 in character to that observed in other glands, both normal and stimulated. 

 As shown in fig. 13, it consisted of a finely granular matrix, in which were em- 

 bedded a number of relatively large vesicular masses. These bodies are cells 

 apparently detached from the epithelial lining. They contain a finely granular 

 cytoplasm which shows in some cases a clear alveolar and in others an irregular 

 structure. Occasionally, as shown in fig. 13, a few small secretion granules 

 may be found in the vesicles. In the figure nuclei are not shown in these bodies, 

 but in other sections the nuclei, usually much shrunken, have been seen. 

 Sometimes free nuclei occur in the secretion. 



In the same figure some of the cells are seen giving off a clear secretion 

 which, as it leaves the cell, assumes the form of a vesicle. In the lumen, how- 

 ever, as indicated in one part of the figure, these vesicles soon lose their regular 

 outline and disintegrate. 



Experiment IV. 



An animal (B) was injected with the usual dosage of pilocarpine and on the 

 following day the injection was repeated. Two days after the first injection 

 the animal was again injected, making altogether three injections at intervals 

 of 24 hours. Immediately before the last injection a portion of the gland was 

 removed and fixed in Kopsch fluid. A second portion was removed and fixed 

 15 minutes after the injection. 



(B 1 ) A Gland Stimulated on Each of the Two Preceding Days. 



This gland was removed immediately before the third injection. After 

 having been twice stimulated at intervals of 24 hours, it had been given for 24 

 hours opportunity to recover from the effects of the stimulation. Examina- 

 tion of the sections showed that it had done this very imperfectly. The gran- 

 ules were found to be rather numerous in the cells of a few lobules, but they were 

 either entirely lacking or exceedingly scarce in most of them. The lumen of 

 the tubules was found to contain a considerable amount of secretion. 



(B 2 ) Gland 15 Minutes Following Third Injection of Pilocarpine. 



Careful examination of the sections failed to reveal granules in any part of 

 the gland. The ducts contained considerable granular material in which dis- 

 integrating cells and vacuolar vesicles were scattered. 



Experiment V. 



Simultaneously with the preceding animal, another individual (C) Avas 

 injected on three successive days. The third injection was made with 0.125 

 grain of pilocarpine. One part of the gland was removed previous to this 



