PAPAVER SOMNIFERUM. 79 



Macaire (Annul, de Chim. et Phys., vol. xxxix. p. 213) states, 

 that the stamens of the barberry and the leaves of the sensitive 

 plant lost their contractility and soon died, when the stems of 

 these vegetables were immersed in an aqueous solution of 

 Opium. Other experimenters have not succeeded in producing 

 this result. By immersing the stem of the Chara in a solution 

 of Opium, the circulation of this plant becomes slower, is soon 

 suspended, and is ultimately stopped (Pereira, op. cit.) 



On Animals. — On all animals Opium has been found to act 

 as a poison, but modified according to the degree of develop- 

 ment of the nervous system. In the Invertebrata, Opium causes 

 weakness or paralysis of the contractile tissues, with gradual 

 sinking and death. Thus in the Polygastrica and the Annelides, 

 it first accelerates the animal movements, but afterwards para- 

 lyses them. Now, in the lower Invertebrata a central nervous 

 apparatus is altogether wanting, while in the higher animals of 

 this class it is not sufficiently developed to exercise that influ- 

 ence over the whole individual which we observe it to possess 

 in the verteb rated class. 



In the vertebrated animal, we have a high development of 

 the central organs of the nervous system, and a consequent 

 increase in the number of symptoms caused by Opium. Thus 

 in fishes, amphibials, and reptiles we observe, in addition to the 

 weakened and paralytic condition of the contractile tissues, 

 convulsions. In the first the convulsive contractions bend the 

 body laterally, whereas in the other Vertebrata the superior 

 dorsal muscles are affected, and hence the head and tail are 

 elevated. These differences obviously depend on the disposi- 



tion of the muscles. Proceeding in the ascending order, we 



observe in birds and mammals, besides the paralysis and con- 

 vulsions, stupor. The last-mentioned symptom, however, is 

 principally manifested in the highest of the mammals, man, 

 that is, in that animal which has the most highly-developed 

 brain; while in some of the lower mammals, as the ruminants, 



it is scarcely observed ; and even in the Carnivora, as in dogs, 



i 



