in Confinement. 3639 



same manner; and if it then proves too light, it is abandoned altoge- 

 ther, and another selected. If a piece is found better fitted for his 

 structure than what he has already obtained, it is rapidly conveyed to 

 the spot; much alteration in the arrangement of the materials takes 

 place, so as apparently to dispose of the new prize to the best advan- 

 tage, and it is only after continued and indefatigable perseverance that 

 he succeeds in rearranging them to his wishes. If there should be 

 any strong fibre which he has a difficulty in causing to remain in the 

 position he requires, a small quantity of sand is brought in his mouth 

 and adroitly placed on the top of it to keep it down ; if this does not 

 effect the purpose desired so as to please him, the refractory piece is 

 taken out and rejected altogether. At times he hangs or hovers close 

 over the surface of the nest, and throws his whole body into a curious 

 and rapid vibratory motion, by which he causes a rapid current of wa- 

 ter to be projected on the materials, as though it were to prove their 

 stability ; and when this operation is performed, the lighter particles 

 and light mud are as it were fanned or winnowed out by the generated 

 current, and may be seen floating away : this operation will also ex- 

 plain the reason for testing the gravity of the materials before they are 

 used. Another very curious operation is the action of drawing his 

 body slowly over the surface of the materials which form the nest. I 

 believe that at this time he excretes a glutinous matter, which acts as 

 a species of cement, and tends to keep the materials together, at the 

 same time that the pressure of his body may render them more com- 

 pact. Or it may be that the whole surface of the nest is by this ac- 

 tion charged with the milt, and thus the impregnation of the eggs more 

 perfectly ensured, as precisely the same motion is employed after the 

 eggs are deposited, and from the appearance of the fish it seems to be 

 attended with pleasurable sensations. These two last-described ope- 

 rations are very frequently repeated. 



If during this time any other male fish makes his appearance, he is 

 chased with the utmost ferocity, and driven to conceal himself in any 

 cranny which he can find; should, however, another fish be also build- 

 ing, desperate battles ensue whenever they approach each other's po- 

 sition, or chance to meet while collecting their materials. 



The whole time occupied in accumulating these materials for the 

 nest was about four hours, during which interval a goodly quantity 

 had been obtained; and a small opening appeared to be carefully con- 

 structed near each end of the mass, the use of which will be now ex- 

 plained. All having been apparently arranged for the female fish to 



