Class conscious - Andrew Martin shops for a rainforest

Pet fish are so old hat. The 1970s . . . that was the Age of Aquariums

The rainforest may be dying out in Brazil (and it's at times like this that I wish I had paid more attention to those magazine interviews with Sting) but north Londoners are doing their bit by putting rainforest installations into their own homes. These can provide a habitat for such rainforest species as Dendrobate frogs and they can also look really good in that bit of dead space between the living-room door and chimney breast.

You can buy a rainforest installation from a shop called digital liquid (note the trendy lower case) on Heath Street, Hampstead, for about £1,500. It might be roughly five foot by three, with a computer-controlled heater, water pump and misting system that simulate rainforest conditions for a limitless period of time. Dendrobate frogs, which could fit inside a matchbox (not that you should try) and are as gaudy as if they were made out of plastic by Mattel, are known to live for at least 20 years, and possibly a lot longer - nobody really knows. This situation reminds me of the 18th-century joke about the man who, hearing that ravens could live for hundreds of years, bought one to find out.

If you invest in a rainforest installation, you will have your very own Amazon.co.uk. You will also be able to stop in his tracks anyone who might be inclined to boast about his greenhouse, because "We can have home-grown tomatoes all year round" is nothing in comparison to "We have a sustainable ecosystem next to our telly". And anyone you know who owns a goldfish will be blown clean out of the water.

Aquariums are also for sale at Digital Liquid, but these seem old hat in comparison with the rainforest installations. The 1970s . . . that was the Age of Aquariums. I associate them with predatory bachelors living in flats with G Plan sofas. The predatory bachelor brings a girl back to the flat and fixes her a drink, which she toys with nervously as he looks into the aquarium, saying: "You know, it's interesting about the Malaysian quinty fish. The parents eat 90 per cent of their own babies . . .Yet they look so charmingly innocent, don't you agree?"

Digital Liquid is a well-designed shop with friendly staff, making it different on at least two counts from the traditional pet shop, in which guinea pigs tremble under fluorescent lights and the owner wears a brown warehouseman's coat, like Michael Palin in the Dead Parrot sketch. There again, old-style pet shops are going the same way as old-style bike shops, which were always presided over by a man in a boiler suit who was so working class that any docket or receipt he wrote out came to you oil-smudged. Now, you don't see oil in bike shops. It's all WD40, which is like an abstract version of oil. Nor do you see nuts and bolts, and I'll bet mudguards aren't called anything as basic as that any more.

In the case of modern pet shops, what has disappeared is the

pets. Increasingly, animals of any size are not for sale, on grounds

of conscience, so the new ones are really pet supplies stores.

A good example of this is Pet on the Archway Road, London N6. It's a very north London shop, in that the toys it sells for puppies are designed to stimulate their brains as well as provide fun; also in that the proprietor, a very bright Islington vet called Russell Hatton, spent £20,000 on the interior design. His lighting, incidentally, is by an Italian company called iGuzzini; the shop logo has won an award in America; and the shop cat (not for sale) is called Garlick. You can buy modernist dog bowls at Pet, and the cat beds come in three styles: Florentine, English Regency or Venetian.

When he opened four years ago, Hatton had the aim of creating

the first pet shop in Britain that was not "naff", and I would say that he's succeeded. Mind you, those cat beds ain't cheap.