INSTINCTIVE BEHAVIOUR IN INSECTS 75 
where the sting can enter. The action does not imply any 
physiological knowledge. In general she begins at the neck. 
Spiders are usually, but not always, stung on the ventral 
surface. To give but one more example, Dr. Peckham ob- 
served in three cases the procedure of Ammophila urnaria 
which preys on caterpillars, and often, after stinging, bites the 
neck in several places, this process being termed malaxation. 
In three observed captures, all the caterpillars being of the 
same species and alike in size, the thrusts were given on the 
ventral surface near the middle line, between the segments, 
In the first, seven stings were given at the extremities (there 
being thirteen segments), the middle Segments being left 
untouched, and no malaxation was practised. In the second, 
Fic. 11.—Solitary Wasp stinging Caterpillar (after Peckham), 
seven stings were again given, but in the anterior and middle 
segments, followed by slight malaxation. In both these cases 
the first three thrusts were in definite order, behind the third, 
the second, and the first segments successively. In the case 
of the third caterpillar, only one thrust was given, between the 
third and fourth segments—that ‘is to say, in the position of 
the first stab in the other cases,—and after this one thrust 
there was prolonged malaxation. Of fifteen stored caterpillars 
examined, some lived only three days, others a little longer, 
while a few showed signs of life at the end of a fortnight. In 
more than one instance the second of the two caterpillars 
