B. STRUCTURAL CHANGES PRODUCED IN THE POISON 

 GLAND BY INJECTION OF PILOCARPINE. 



By Henry Fox. 

 (With the collaboration of Leo Loeb.) 



In order to study the different stages of activity of the poison gland of 

 Heloderma under various conditions, the animals were injected subcutaneously 

 with pilocarpine. The general effects of the pilocarpine were strikingly similar 

 to those described in the case of salivary glands. (See Cohoe, Jour, of Anat., 



vol. VI.) 



Experiment I. 



An animal (No. 1) was for the first time injected with 0.1 grain of pilocar- 

 pine. Immediately before the injection a portion of the poison gland was 

 removed and fixed in Kopsch fluid to serve as a control. The animal was then 

 injected and three pieces of the gland were removed at intervals of 15, 35, and 

 50 minutes, respectively. 



(1a) Gland Removed Previous to the Injection. 



This was found upon microscopic examination to be entirely normal. 

 Numerous granules were observed crowding the cells of the intralobular tubule, 

 the undifferentiated cytoplasm being limited to an extremely thin layer at the 

 base of the cells. A copious granular secretion was found in the lumina of the 

 tubules, but it is doubtful if this condition is normal it may have been forced 

 out of the cells into the tubules as a result of the handling consequent upon the 

 removal of the gland. 



(1b) Gland Removed 15 Minutes after Injection of Pilocarpine. 



Sections showed most of the intralobular duct cells devoid of granules, 

 though a moderate number retained a feAv. As a rule the cells presented the 

 usual character of stimulated gland-cells, being quite or almost free of granules 

 and with large, clear vacuoles inclosed in the meshes of the cytoplasmic retic- 

 ulum. Within the tubules the amount of secretion visible was extremely small, 

 in marked contrast to the quantity observed in the normal gland. If the latter 

 condition was normal, one evident effect of the stimulation with pilocarpine 

 was a rapid solution of the extruded granules or an expulsion of the secreted 

 material from the gland proper. One remarkable feature of pilocarpine stimu- 

 lation shown in this case is the extreme rapidity of its action as compared with 

 its action on salivary glands. According to Cohoe, the submaxillary gland 

 of a rabbit showed all the granule-cells loaded with granules after 3 hours' 

 stimulation with a dosage of 0.014 gm. per kilo of body-weight of the animal. 



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