FORMATION OF WEIRS. 15 



some of these fish in a reservoir in his hothouse, but lost 

 his brood regularly from this cause, till he placed some 

 water-plants in the reservoir last year, and thus secured the 

 stock. Few persons are aware of the cause of the death of 

 these beautiful little fish when kept in the globular glasses, 

 even where much care is bestowed upon them. It is sim- 

 ply this, they become heavy in spawn, and not being able 

 to rid themselves of the egg, for want of the assistance 

 which plants afford in the act of parturition, inflammatory 

 action takes place in the ovarium, mortification ensues, and 

 death is the consequence. 



Returning to the subject of the restoration of rivers, I 

 should decidedly say, that all weirs should be wholly re- 

 moved, or else that they should be formed upon such prin- 

 ciples that every sort of fish may be able to surmount these 

 obstacles, and ascend the stream for the purpose of spawn- 

 ing ; and this may easily be accomplished, if, in a navigable 

 river, the one side be arranged for the lock, and the other 

 side for the weir, of long inclination, without any further 

 barrier ; or if again, on another principle, zigzag flights of 

 steps be made, upon each of which steps the fish would 

 have time to rest and recover its strength for a further leap, 

 and, overcoming all obstacles, at last push forward for the 

 clear spring or pure water. I point out these plans to show 

 that, if artificial spawning, breeding and rearing be adopted 

 at all, it would be wise, while you are about it, to give the 



