FiTCHETT. — Physiological Action of Tutin. . 323 



Breathing of the Cheyne-Stokes type occurred in some experiments, the 

 climax of the period of respiratory activity corresponding to the highest 

 point of the Traube-Hering curve, which appears simultaneously. 



{d.) Urinary System. 



Micturition was a marked feature in cats poisoned by tutin. It occurred 

 voluntarily several times before convulsions occurred, and during the con- 

 vulsions (and this is true also of rabbits and gmnea-pigs) involuntary 

 discharges of urine occurred. In the majority of cases the bladder was 

 found distended after death, even where a free discharge of urine had taken 

 place during the convulsions. This points to an increased secretion of 

 urine. Attempts were made to estimate the rate of flow in anaesthetised 

 animals (Exps. 144, 145). but without satisfactory results. 



This increased secretion pointed to the possibility of tutin being elimi- 

 nated in the urine, and so an attempt was made to recover tutin from the 

 urine of poisoned animals. The urine was collected by incising the bladder 

 after death. It was evaporated to dryness and exhausted with ether, but 

 no crystals of tutin could bei detected on evaporating ofT the ether. The 

 residue from the ethereal solution was in one case dissolved in saline and 

 injected under the skin of a frog (Exp. 151), but with negative results. 

 The urine was in several cases examined for abnormal constituents, but 

 none was found. 



{e.) Genital System. 



Many of the animals experimented upon were pregnant females in 

 different stages of pregnancy, but in no case was abortion observed, although 

 the animal was under the action of the poison long enough for it to occur. 



(/.) Nervous System. 



The symptoms that appear in animals poisoned by tutin point clearly 

 to the central nervous system as the part of the body that is specially affected 

 by the action of the poison. The two cardinal symptoms are convulsions 

 and a dulling or blunting of the mental faculties that in the early stage 

 makes the animal appear dazed and stupid, and in the later stages passes 

 into actual coma. 



Convulsions. — The convulsions are obviously of central origin. They 

 bear a close resemblance to an ordinary epileptic fit, which is generally 

 held to originate in the cortex. Whether the tutin convulsions originate 

 in the cortex or not, it is certain that the nerve-cells in the basal ganglia, 

 pons, medulla, and cord are profoundly affected. This is shown by the 

 action on the vomiting centre, respiratory centre, and cells of the cord. 

 Among the first symptoms to appear are twitching of the ears, blinking of 

 the eyes, and movements of the lips. These are followed by jerking of the 

 head and movements of the fore and hind limbs. These movements may be 

 attributed to irritation of the cells of either the upper or the lower motor 

 neurones. In order to determine more accurately the site of action the 

 follo^^'ing experiment was made :• — 



(Exp. 152.) The right cerebral hemisphere was exposed in a cat and 

 a large dose of tutin injected hypodermically. When general convulsive 

 movements had developed, the right cerebral hemisphere was removed. 

 Now, had the convulsions been cortical in origin, one would expect them 

 to have ceased on the left side of the body ; but they continued as before. 



