Instinct and its Lessons 1 1 7 



is not confined to the foster-parents. In the case of a 

 young Cuckoo, which he watched, not only did the 

 Hedge-sparrows responsible for it attend to its require- 

 ments, but a Greenfinch, which had nothing to do with 

 the business, came to help them. He tells us that in 

 another case, when a young Cuckoo was hung up in a 

 garden in a parrot cage, two Wrens, which were building 

 near, came, and, getting through the bars, commenced 

 to feed him : being presently joined in the office by a 

 pair of Hedge-sparrows. Even when they had finished 

 their own nest, one of the Wrens continued to feed the 

 young monster. Such an instinct can clearly do nothing 

 to serve the fortunes of the race which exhibits it, for 

 the young Cuckoo commences his career by the destruc- 

 tion of the young birds in the nest he occupies : being 

 therefore taken by the greatest of observers as the type 

 of a thankless usurper's treatment of his dupes ; 



And being fed by us, you used us so, 



As that ungentle gull the Cuckoo's bird, 



Useth the Sparrow : did oppress our nest : 



Grew by our feeding to so great a bulk, 



That even our love durst not come near your sight. 



Now, leaving the question of their origin, we have 

 to examine the other question as to the transmission 

 of instincts. Is it conceivable that they should 

 descend from one generation to another unless there 

 were in the creature's nature something tending to 

 induce the descent? Can that something be any- 

 thing but the machinery of purpose to secure an end? 



Some of the examples already cited, under the 

 first head of our inquiry, will serve to introduce us 

 to the second. Most remarkable of these is the 

 care of neuter insects, which, doing nothing to 

 propagate their race, can do nothing to transmit 

 instinct or anything else. Yet these neuters do all 

 the work of the community, and require the most 

 complicated instincts to do it. To fit them for their 

 object, even their bodily form has often to be 



