"Nobody ever became a comedian because he's trying to bring happiness to people," observed the veteran stand-up Jackie Mason a few weeks ago. "He's trying to bring cash to the bank." These days he (and she) probably find that easier than it used to be, thanks to a boom in stand-up which has turned every other pub into a comedy club and spattered the television schedules with spin-offs, specials and light entertainment quizzes. It has been a good decade for those who used to sit at the back of the class and make their friends snort uncontrollably in the middle of lessons - I hardly dare think how many teachers have had their sarcastic remarks repeat on them uncomfortably as they see old pupils hit the headlines ("Oh very clever, Izzard. That will stand you in good stead when you've got a mortgage to pay.") You really know a new generation has come of age, though, when they start making nostalgic documentaries about the early days of struggle. Channel 4 is doing just that at the moment (and taking the opportunity to blow its own trumpet) with First on Four, a series of films "celebrating" the career of comics closely associated with the channel.

The makers of these films said somewhere that they weren't interested in churning out yet another cosy career retrospective, with no sense of the battle to perfect material and overcome discouragement. To that end both programmes so far have included dissenting voices - though they're of a decidedly cosy kind. In last week's programme about Harry Enfield, for instance, the comedian's father popped up now and then to encore his popular turn as Censorious Old Git, while this week Paul Merton offered a dead-pan character assassination of Julian Clary ("Fanny the Wonder dog was the one with the talent"). This had all the cutting edge of a Scotch pancake - it had the appearance of sharpness but turned out to be rather sweet and yielding, the sort of insult which is dependent on well-established affection between old friends.

And this week's programme was a bit less persuasive than last week's opener - partly because Clary doesn't seem to be quite grand enough to warrant the "comedy great" treatment, partly because of a certain thinness on the testimonial side. In the programme about Enfield you didn't need captions to tell you who the old associates were - since they had all become famous in their own right through The Fast Show. Their presence confirmed the sense of a whole community of talent working its way towards recognition. Here the producers had to rely on a former commissioning editor for comedy, a script-writer and the star's costume designer - none of whom could exactly be described as household names. What's more, because Enfield has moved his career on with such discipline, abandoning successful characters before their popularity peaked, there was a real charge of nostalgia in seeing the old favourites again. In Clary's case the act has remained essentially unaltered - 10 years ago he came out of the closet (Zsa Zsa Gabor's closet, by the look of it), and took the vintage motor of British innuendo for a reckless spin down some back roads. Today he's doing pretty much the same. Still, he's a very nice man and he could put a crease in a nun's wimple without offending her - so the programme was enjoyable even if not particularly enlightening. In another 10 years maybe Sandie Kirk, producer of Gas, Channel 4's current stand-up showcase, will be recalling the heady moment when X or Y first trod the boards. But I don't think she will be doing it about any of last night's contributors, all of whom were funny but all of whom also showed the heavy influence of existing stars. Chris Addison has been learning from Eddie Izzard's free-fall monologues, while Noel Fielding has blended bits of Harry Hill surrealism with Lee Evans's nervous shamble. Hovis Presley was less easy to place - a large man who stared suspiciously at the audience as if they might be a mental health tribunal, and who delivered slightly gnomic shards of comedy alongside old-fashioned comic verse. He made me laugh, but despite the name I think he's probably an acquired taste.