ORIGIN AND DEVELOPMENT OF INSTINCTS. 179 



cannot do better than confine myself to making a quotation 

 from Mr. Darwin's MSS ; for this will show how deep-seated 

 and detailed is the resemblance between habit and instinct. 



" In repeating anything by heart, or in playing a tune, 

 every one feels that, if interrupted, it is easy to back a little, 

 but very difficult suddenly to resume the thread of thought 

 or action a few steps in advance. Now P. Huber has described 

 a caterpillar which makes by a succession of processes a very 

 complicated hammock for its metamorphosis; and he found 

 that if he took a caterpillar which had completed its ham- 

 mock up to, say the sixth stage of construction, and put it 

 into a hammock completed up only to the third stage, the 

 caterpillar did not seem puzzled, but repeated the fourth, 

 fifth, and sixth stages of construction. If, however, a cater- 

 pillar was taken out of a hammock made up, for instance, to 

 the third stage, and put into one finished to the ninth stage, 

 so that much of its work was done for it, far from feeling 

 the benefit of this, it was much embarrassed, and even 

 forced to go over the already finished work, starting from the 

 third stage which it had left off before it could complete its 

 hammock. So, again, the hive-bee in the construction of its 

 comb seems compelled to follow an invariable order of work. 

 M. Fabre gives another curious instance how one instinctive 

 action invariably follows another. A Sphex makes a burrow, 

 flies away and seeks for prey, which it brings, paralyzed by 

 having been stung, to the mouth of its burrow ; but always 

 enters to see that all is rioiit within before drac^s^imy in its 

 prey; whilst the Sphex was within its burrow, M. Fabre 

 removed the prey to a short distance ; when the Sphex came 

 out it soon found the prey and brought it agaiu to the mouth 

 of the burrow ; but then came the instinctive necessity of 

 reconnoitering the just reconnoitered burrow ; and as often 

 as M. Fabre removed the prey, so often was all this gone 

 over again, so that the unfortunate Sphex reconnoitered its 

 burrow forty times successively ! When M. Fabre altogether 

 removed the prey, the Sphex, instead of searching for fresh 

 prey and then making use of its completed burrow, felt itself 

 under the necessity of following the rhythm of its instinct, 

 and before making a new burrow, completely closed up the 

 old one as if it were all right, although in fact utterly useless 

 as containing no prey for its larva.* 



* Anns, des Sci. Kaf., 4 ser., tome vi, p. 148. "With respect to Bees, see 



M 2 



