Account of the Nest of Sticklebacks. 323 



them together by means of the mucus which exudes from his 

 skin. By means of this operation the first collected ma- 

 terials form a kind of foundation or solid floor on which the 

 rest of the edifice is to be reared : the execution of this he 

 continues with a feverish perseverance and agitation. In 

 order to satisfy himself that all the parts are sufficiently 

 united, he agitates his pectoral fins with great rapidity, in 

 in such a manner as to produce currents directed against the 

 nest, and if he notice that the pieces of grass are moved, he 

 presses them down with his snout, heaps sand upon them, 

 flattens them, and glues them together again. 



*' When the process has reached this point he chooses more 

 solid materials. We then see him seize small pieces of wood, 

 sometimes straws, which he takes up with his mouth, and 

 presses them into the thickness, or places them on the sur- 

 face of the first construction. If he finds, when attempting 

 to introduce them, that the position he has given them does 

 not sufficiently answer his purpose, he draws them out again, 

 seizes them at another part, again inserts them, pushes them 

 forwards, until he judge that he has made the best possible 

 use of them. Occasionally, however, in spite of all his care, 

 there are parts which, owing to their shape, he cannot get to 

 enter into the general plan of the edifice. These he draws 

 out, carries to a distance from his nest and abandons ; then 

 proceeds to select others to supply their place. In this 

 manner he finishes by hollowing out a solid bed, the difl*erent 

 component parts of which he has always the precaution to 

 solder together by means of the viscous matter which serves 

 as glue. 



" When he has succeeded in constructing in this way the 

 floor and side-walls of his edifice, he then undertakes the roof- 

 ing; and for this purpose he continues to carry materials 

 similar to those used in laying the foundations. But while pur- 

 suing the completion of his enterprise with the most laborious 

 activity, he does not neglect to secure at the same time its con- 

 solidation, and, with that view, he continually repeats the 

 fatiguing manoeuvre of the vibratory creeping, by means of 

 which, as has been hinted, he agglutinates the various 

 materials composing his nest. But in proportion as he 



