23 



Poison with Laurel Leaves. 

 Under this title, the Secretary read the following note from Mr. Newman : — 



" I have two favourite theories with regard to insect-killing: first, that man, not 

 being constructed on the same plan as an insect, has very little chance of judging 

 correctly as to the extent or quality of its sufferings under any circumstances : secondly, 

 that man has no right whatever to inflict unnecessary suffering on any creature, and 

 may not assume that sensation exists not, because he perceives it not. Entertaining 

 these views, I have watched with much interest the effects of laurel-leaf poison on 

 divers insects subjected to its agency : these are very similar in all insects ; a state of 

 coma is speedily induced, and this gradually assumes the phase of peaceful unsuflfering 

 death. I will try to pourtray the scene in the instance of a perfectly vigorous female 

 of Arge Galalhea. Immediately on being placed beneath the inverted tumbler, it 

 settled on the gauze covering of the bruised laurel-leaves, and walked about very 

 sedately, occasionally opening and shutting its wings, as if under the influence 

 of genial sunshine. It soon ceased walking, but the wings still moved occasionally; 

 and the convolute maxillae were unrolled, and their tip seemed to be feeling about in 

 search of food: presently the said tip was immersed in a drop of fluid exuding from a 

 recent wound in the laurel stem ; a very small quantity was imbibed, and more was 

 sought very assiduously, but seemingly without success. I once observed the first pair 

 of legs porrected, and being held close together, the maxillae were introduced between 

 them and withdrawn several times in succession : this was new to me, as I do not 

 recollect having before seen the fore-legs of a pseudo-tetrapod butterfly used for any 

 purpose whatever: in this case they appeared as cleansing instruments, and reminded 

 me a little of the velvet-cushioned paws of a cat, as used after her lips had been 

 sprinkled with milk, a constant result of lapping that favourite beverage. A state of 

 rest succeeded this cleansing, during which the butterfly inclined on one side, as though 

 unable to maintain an erect position; and the angle of inclination increased very 

 gradually, until in about an hour and a half the insect fell on its side ; the slight shock 

 of the fall was followed by a few gentle movements, the most notable of these being 

 the reversal of the wings, the under sides of which were brought into approximation, 

 not contact, beneath the body ; the legs being, by the same movement, quite deprived 

 of their locus standi. Life was extinct, and from first to last there had not been the 

 slightest indication of suffering. I do not theorise as to the immediate cause of death : 

 I do not assert that, because the insect sipped the laurel-juice, it committed either 

 intentionally or unintentionally an act oi felo-de-se : the very atmosphere of a tumbler 

 inverted on bruised laurel is impregnated with deadly poison in a gaseous state, and 

 this enters the system through the spiracles as readily as a liquid through the 

 conjoined maxillae." 



Mr. Smith always found the bruised laurel-leaves killed Hymenoptera very 

 speedily. He could not agree with Mr. Newman, that, in the case of the butterfly 

 alluded to, the process which took an hour and a half to destroy life was not attended 

 with suffering. 



Mr. Douglas said that a short time since he had placed a number of Coleoptera, 

 amongst which was a specimen of Necrobia ruficollis, in a bottle containing bruised 

 laurel-leaves : after a lapse of several days he had found the Necrobia still alive. 



