452 Profs. A. Alcock and L. Eogers. On the Toxic [Apr. 28, 



breathing having stopped, though the heart continued to beat faintly. 

 Twenty-two minutes after the injection the heart stopped. 



Experiment 9. — A white rat was injected with 1 c.c. of watery 

 extract of one parotid gland of the same Zamenis used in Experiment 8. 

 No untoward symptoms occurred. 



v. Tropidonotus piscator. 



Experiment 10. — A small white mouse was injected under the skin 

 of the back with an extract of both parotid glands of two small 

 specimens of this species, made with 4 minims of normal salt solution. 

 Before the injection the respirations were thirty -six in 15 seconds. 

 Seven minutes afterwards the respirations were thirty-five in 15 seconds 

 and deeper, and at 13 minutes the respirations became laboured and 

 the animal restless. From the 18th to the 23rd minute the respira- 

 tions became more and more laboured, and increased from thirty-seven 

 to forty in 15 seconds, the animal's restlessness and distress also 

 increasing. At the 32nd minute the respirations, which were deep, 

 had fallen to thirty-three in 15 seconds, the animal half reclining. 

 A minute afterwards the respirations, which were very deep and 

 forced, were twenty in 15 seconds. Convulsions then began, during 

 which the animal rolled over and nearly stopped breathing. At 

 34 minutes breathing ceased, and just before the 36th minute from 

 the moment of injection the heart stopped. 



Post mortem. — There was marked extravasation of blood. 



Experiment 11. — A small black-and-white mouse was injected under 

 the skin of the back with the extract in distilled water of one parotid 

 gland of a large Tropidonotus piscator. The fluid consisted of thick ropy 

 mucus. Except that its respirations rose rather irregularly from thirty 

 to forty in 15 seconds, and that it scratched itself violently at the site 

 of the injection, the animal seemed for a long time to be all right. At 

 77 minutes the respirations were thirty-six in 15 seconds, and the animal 

 seemed to be somewhat sleepy. At 92 minutes the animal was dis- 

 tinctly sleepy, moving sluggishly on being stirred, and dragging the 

 hind legs. After this the animal could not be watched, but next- 

 morning (15 hours after the injection) it was found dead in its cage. 



Experiment 12. — As a control experiment, a white mouse, of the 

 same size as the one used in Experiment 10, was injected under the 

 skin of the back with an extract in 4 minims of normal salt solution 

 of both Harderian glands of both the specimens of Tropidonotus used 

 in Experiment 10. The animal was closely watched for 40 minutes, 

 but no ill-effects were observed. It was then put into its cage and 

 looked at from time to time, but it was still quite well and active 6 

 hours after the injection, and next day its condition was quite normal. 



Experiment 13. — As a control experiment another white mouse, of 



