220 VENOMOUS ANIMALS : PROTOZOA TO ARTHROPODA 



contents of the abdomen. The second opening, which lies along- 

 side the first, belongs to a small, irregular, tubular gland called the 

 alkaline gland, or gland of Dufour. The third opening, when 

 present, leads into a lanceolate or ovoid accessory poisonous gland. 



The Venom. — ^The venom freshly extruded from the bee's body 

 weighs from 0-2 to 03 milligramme, and is a transparent acid fluid 

 with a bitter taste, a peculiar aromatic smell, and a specific gravity 

 of 1-1313. It contains about 30 per cent, of solid matter when 

 dried at the room temperature. 



The acid reaction is believed to be due to formic acid, and the 

 smell to volatile substances, but neither of these have any connec- 

 tion with the poisonous properties of the venom. 



The preparation of venom in quantity was carried out by Langer 

 as follows: Several thousand fresh stings with their venom-sacs 

 were placed in 96 per cent, alcohol, which was in due course filtered 

 off, when the stings were dried at 40° C, then pulverized and 

 extracted with w^ater. The resulting extract, which, when filtered, 

 was a clear yellowish-brown fluid, was then precipitated by 96 per 

 cent, alcohol. The precipitate, after washing with alcohol and 

 ether, was dissolved either in ordinary water or in the same acidu- 

 lated slightly with acetic acid. From this solution Langer obtained 

 an albumin-free active body after repeatedly precipitating with 

 a few drops of concentrated ammonia and again dissolving as 

 above. The active principle is, therefore, not albuminous, and 

 is thought to be an organic base, the nature of which, however, 

 is not known. This poison is destroyed or its activity lessened 

 by oxidizing agents, such as potassium permanganate, and also 

 by ferments, such as pepsin and rennin. 



Subcutaneously injected, the venom produces great local irrita- 

 tion, but heating to 100° C. for fifteen minutes destroys this effect. 



Intravenous injections into dogs produce convulsions, trismus, 

 nystagmus, emprosthotonos, and death from respiratory failure. 

 This action is believed by some authors to be due to a neurotoxin, 

 but the blood after death is very fluid, and the red corpuscles are 

 destroyed, indicating a marked haemolysis, while all the organs 

 except the spleen show haemorrhages and hyperaemia; so that the 

 effects may not be due so much to the action on the nervous system 

 as to that on the blood. The convulsive effects can be destroyed 

 by heating to 100° C. for thirty minutes, when the poison becomes 

 merely narcotic. All effects are annulled by heating to 150° C. 

 for fifteen minutes. 

 The venom, therefore, contains : — ■ 



1. Inflammatory poisons, which are thought to come from the 

 acid gland. 



2. Neurotoxins: — • 



(1) Convulsive, thought to be derived from the alkaline 



gland. 



(2) Narcotic, secreted by the acid gland. 



3. Haemolysins. 



