THE YOUNG NATURALIST. 



167 



shallow water, and would often come up to the top of the aquarium, and 

 remain for a long time in water barely more than half sufficient to cover if. 

 I had it for a year or two, when it was accidently killed. I once kept one 

 for a few months longer than this one, and mirabile dictu ! my aquarium in 

 this case was only a common earthernware basin. This individual came 

 eventually to an untimely end by means of a shore crab, who lived with him 

 contentedly for many months, but at last treacherously murdered his com- 

 panion. 



How beautiful is this pellucid pool which the tide has left. Look at the 

 abundance of life it contains. Shrimps in numbers, freckled gobies ( Gohius 

 minutus), excellent pets for an aquarium and very tameable. And look there 

 at those curious fish swimming about perpendicularly in the water. They are 

 the pipe fish {Syngmthus acus), and very curious creatures. I find a difficulty 

 in keeping them alive for any great length of time. The reason seems chiefly 

 to be I find it far from easy to feed them. In the summer time when I can 

 take day trips to the sea side and bring home abundance of sand from below 

 the level of ebb tide, and seaweed with plenty of minute crustaceans on it, 

 they do very well. They scoop the sand up with their noses, and search out 

 the minute creatures in it and on the algae, and so find sufficient food to 

 support life ; but when the excursion season is over a journey to the sea side 

 is very expensive, and I cannot get the Syngnathi to eat scraped meat like 

 the other fish, and so they die of inanition. 



I collect algse in some quantity for the sake of such creatures as feed upon 

 it, but I think an aquarium flourishes best with a minimum quantity of it. 

 This I know is contrary to the popular opinion, for it is generally supposed 

 that abundance of TJlva latissima and other seaweeds is of benefit to the 

 creatures in a marine aquarium, but I have some doubt of this. Certainly they 

 improve its appearance, and I like to see them ; moreover, they afford shelter 

 to the fish, prawns, &c, and it is impossible to keep the herbivorous mol- 

 lusca and alga-loving species of Crustacea without a supply of them. We 

 constantly read that they oxygenate the water, and thus supply the needful 

 quantity of the life-giving gas. So they do in bright sunshine cer- 

 tainly. When the sun shines on the aquarium they give off oxygen most 

 profusely, but on a cloudy day they give off none at all, but I find on the 

 contrary, a small quantity of carbonic acid gas. Given therefore a super- 

 abundance of seaweed, and a succession of cloudy days, and there may be 

 ■—it is easy to conceive — together with that produced by the respiration of 

 the inmates, a quantity of carbonic acid gas generated sufficient to suffocate 

 every one of the creatures. 



I had at one time in my aquaria, and this be it remarked is but a small 



