450 



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



iii. Dryophis mycterizans. 



Experiment 4. — A small black-and-white mouse, whose respirations were 

 about twenty-five in 15 seconds, was injected under the skin of the back 

 with an extract of one parotid gland, in 4 minims of normal salt solu- 

 tion, of a full-grown snake. Two minutes afterwards the animal was 

 restless, 3 minutes afterwards it was restless and twitching, and 

 5 minutes afterwards it was sleepy and nodding. At the 7th minute it 

 was again restless, and the respirations, which were thirty-eight in 

 15 seconds, were deep. Twitching continued ; but at the 16th minute, 

 though the animal looked sleepy and dejected, it could walk fairly 

 well, and appeared to be improving. 



At the 26th minute a similar extract of the other parotid gland of 

 the same snake was injected in the same way. At the 29th minute the 

 animal was again sleepy, and its respirations were thirty-eight in 

 15 seconds. At the 37th minute it was very sleepy. At the 48th minute 

 it lay quite quiet with its nose on the table, the hind legs appearing to 

 be weak. At the 52nd minute it could not stand, and the respirations 

 were slow and deep. At the 55th minute the respirations were only 

 five in 15 seconds, and of a gasping character, and the animal lay help- 

 less on its side. At the 56th minute convulsions occurred, and respira- 

 tion then ceased, and just before the 57th minute after the first 

 injection the heart stopped. 



Post mortem. — There was most extensive extravasation of blood 

 under the skin of the back and head. 



Experiment 5. — A medium-sized black-and-white mouse was injected 

 under the skin of the back with the extract of both parotid glands of a 

 full-grown Droyophis mycterizans made by means of 4 minims of a normal 

 saline solution. At the 2nd minute the animal was excited ; at the 5th 

 minute it was nodding, its respirations being then thirty-seven in 15 

 seconds ; and at the end of a quarter of an hour it was still sleepy and 

 breathing at the same rate, though deeper than before, with occa- 

 sional twitching. At the 28th minute it was quiet, but subject to starts, 

 its respirations being thirty-eight in 15 seconds, and of a laboured and 

 occasionally convulsive character. At the 32nd minute the hind legs 

 were weak, and walking was slow and difficult : the respirations were 

 thirty -five in 15 seconds, and laboured. At the 35th minute the hind 

 legs were paralysed and sprawling, and walking was impossible : the 

 respirations were thirty-four in 15 seconds, and very deep. At the 37th 

 minute the animal could just stand with its nose resting on the table : 

 the respirations were thirty -two in 15 seconds, laboured, and occasionally 

 convulsive. At the 39th minute the respirations had fallen to twelve 

 in 15 seconds, and were very laboured : general convulsions then set 

 in, the animal rolled over on its side, and breathing stopped. Forty 

 minutes after the injection the heart stopped also. 



