330 THE ZOOLOGIST. 



were bound with wire, and when threshing, the wire from each 

 sheaf was thrown into a heap. In one district only a few giant 

 eucalypts remained in the fields, and as a natural consequence 

 twigs became very scarce. In their plight the Magpies took to 

 building their nests with wire cut from the sheaves. Some years 

 later string binders superseded wire, and the Magpies had to 

 make shift the best way they could. Wire was certainly a 

 "foreign" substance; if the birds had been guided by mere 

 blind " instinct," they would not and could not have come to 

 such a substitute for twigs. The mere fact of their escaping an 

 awkward predicament indicates that they were endowed with 

 something more than " instinct." An English paper stated a 

 few years ago, that at Stoke Newington Priory the use of wire for 

 nests by the Herons was increasing, and that in the preceding 

 spring nine out of sixteen nests were constructed with wire. 

 There are records of other species of birds building with wire, 

 and such like substances, when there was no apparent necessity 

 for it ; but in our utter ignorance of the birds' motives we should 

 hesitate before calling such proceedings mere freaks without 

 rhyme or reason. Dr. Carpenter mentions an incident which he 

 terms " a very good example of intelligential modification of the 

 instinctive tendency." The incident* is : — " A pair of Jackdaws 

 endeavoured to construct their nest in one of the small windows 

 that lighted the spiral staircase of an old church tower. As is 

 usual, however, in such windows, the sill sloped inwards with a 

 considerable inclination, and consequently, there being no level 

 base for the nest, as soon as a few sticks had been laid, and it 

 was beginning to acquire weight, it slid down. This seems to 

 have happened two or three times ; nevertheless the birds clung 

 with great pertinacity to the site they had chosen, and at last 

 devised a most ingenious method of overcoming the difficulty. 

 Collecting a large number of sticks, they built up a sort of cone 

 upon the staircase, the summit of which rose to the level of the 

 window-sill, and afforded the requisite support to the nest; this 

 cone was not less than six feet high, and so large at its base as 

 quite to obstruct the passage up the staircase ; yet, notwith- 

 standing the large amount of material which it contained, it was 

 known to have been constructed within four or five days. Now, 



* hoc. cit. p. 86. 



