Page:The Zoologist, 1st series, vol 4 (1846).djvu/396

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1562
Insects.

"remove the pin and its struggles will cease." He does not explain (because he cannot tell) why the struggles took place;* but, assuming (which he has no right to do) that they took place simply from a desire "to escape," he proceeds to give his reasons why they ceased when the pin was extracted, and says he shall be "content" with either.

Let us now examine his two reasons. The second is evidently er- roneous, for, if the "struggles ceased" because the creature found it- self " at liberty," or, which is the same thing, if they commenced (which, as before intimated, he "tacitly assumes") because it was not at liberty ; i.e. to say, if they commenced simply from a desire " to escape " (it being the proper time for the insect to fly away) ; directly the hinderance was removed, it would fulfil its desire and fly, and Mr. Turner would have had no opportunity of seeing whether its "strug- gles ceased" or whether they did not. Hence, it could not have struggled merely from a desire "to escape."

His first reason is most extraordinary and inexplicable. If the "struggles ceased" because the "pin-wound caused no pain," — why, we ask, were they produced while the pin was actually in the wound and irritating it? Besides, if the "pin-wound caused no pain," there is no reason why the insect should flutter a bit more when the pin was in than when it was out (inasmuch as, be it particularly ob- served, it had no desire " to escape," that being the second indepen- dent reason which he liberally gives us the choice of). If it strug- gled (as he allows it did) while the pin was actually in the wound, and ceased struggling when it was out ; it clearly proves, that, being re- lieved from the pain caused by the pin irritating the wound, upon its being taken out it was comparatively at rest.

Hence, Mr. Turner states correctly the natural progress of an im- paled moth (i.e. in the extreme case which he has taken, of the in- sect slumbering on until its proper time for awaking ; and which, as he has found it to take place at times, I willingly concede to his ob- servations) ; but he has fallen into error in his after deductions, and assumed the only important part of his [whole proposition, viz., the reason why the struggles commenced, and declared it to be solely


I separate this case altogether from Mr. Turner's other instance, which we have just discussed. For the cause of the struggles which he there assumes (viz., the pres- sure exerted at the time they are impaled) is only applicable to insects awaking at the moment the pin is inserted. We are now examining his second example, where the impaled creature has been slumbering for hours, and, on awaking at its accustomed time, discovers its unpleasant position.