The Modern Theory of Instinct 



On the second occasion, moreover, I had 

 my first view of the squeezing process to 

 which the caterpillar's brain is subjected, a 

 process that produces the torpor which makes 

 the transport and storage of the victim pos- 

 sible. So remarkable a fact would not have 

 escaped me in the first instance; it did not, 

 therefore, take place. It follows that this 

 cerebral compression is a resource which the 

 Wasp has at her disposal, for use when cir- 

 cumstances demand it, as for instance when 

 the victim seems likely to offer resistance on 

 the road. 



The malaxation of the cervical ganglia is 

 optional: it has no bearing on the future of 

 the larva; the Wasp practises it, when need- 

 ful, to facilitate transport. I have seen the 

 Languedocian Sphex, who gave me so much 

 trouble in the old days, at work fairly often, 

 but only once has she performed this opera- 

 tion on the neck of her Ephippiger in my 

 presence. The invariable and absolutely 

 necessary part of the Hairy Ammophila's 

 procedure seems therefore to be the multi- 

 plicity of stings and their distribution one by 

 one over all or nearly all the nerve-centres 

 along the median line of the lower surface. 



Let us place side by side with the murder- 

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