The Zoologist — Septembek, 1873. 3673 



at first the amount of vital energy was excessive, far too great, but 

 it was the old story, the sword wore out the scabbard ; more 

 frequently complete success was the result. We will suppose a 

 dozen of these little fishes turned into the upright aquarium I have 

 described ; an hour will scarcely elapse before one of the fiery 

 redbreasts asserts himself master, selects a part of the establishment 

 "for building purposes" and drives off all intruders: if a second 

 redbreast should call his supremacy in question and contest the 

 point, he must be removed at the risk of disarranging the establish- 

 ment, but this disarrangement is of less importance than it appears : 

 after stirring up the contents of the glass in a most violent manner 

 in your determination to eject an objectionable tenant of any kind, 

 they will settle down in half an hour and arrange themselves as 

 prettily and as naturally as before you converted their dwelling- 

 place into a miniature Maelstrom. Leaving one redbreast master 

 of the situation, he immediately commences building operations, 

 but at first these operations do not seem to be conducted on any 

 definite plan ; and you begin to think the work is aimless and 

 objectless : half a dozen nests will be begun and deserted ; the 

 structure is then pulled to pieces and the materials are carried 

 elsewhere : what are these materials ? little gravel-stones, roots of 

 water-plants, hair-like Confervae spontaneously generated out of 

 nothing, decaying leaves of Valisneria, and all manner of frag- 

 ments, which we should characterize as rubbish : by-and-bye an 

 event occurs, unseen and unnoticed, which concentrates all the 

 attentions of the redbreast to one spot: this event is the deposition 

 of spawn by a gravid female ; I could never witness the operation, 

 but have no doubt whatever that this event is the governing cause 

 of future proceedings : a foundation, a circular wall or rim, is then 

 constructed around the precious deposit, and this is increased, and 

 improved, and consolidated, in the most wonderful manner, the 

 builder being incessant in his labours ; sometimes he will bite off 

 a root of the duck-weed or frog's-bit, and will set it floating in the 

 water; he will then contemplate this fragment, remaining stationary 

 at a little distance, and will hover like a kestrel over a mouse, sup- 

 ported by the incessant fan -like motion of his pectoral fins : should 

 the fragment bear this rigid inspection he proceeds to utilize it; 

 sometimes, however, the fragment does not meet with his entire 

 approval, and then it is at once abandoned. Mr. Kinahan has 

 observed that after a fragment has been thus abandoned by one 



