IT'S QUITE an experience to read the more than 400 pages of letters in Wild Gooseberries: The Selected Letters of Irving Layton (Macmillan, 448 pages, $29.95 cloth), edited by Francis Mansbridge. What makes it such an experience is the pounding egoism of the man, his unending insistence on his own genius, his constant ebullient hollering at his correspondents about what a lusty devil and magnificent poet he is, and his famous anger -- which actually takes two forms: one a sort of lofty patronizing of his correspondent, in which the correspondent is little, small, a feeble stick, thin, weak, silly, timid, genteel, etc., etc.; and the other a venomous, hissing attack that is simply -a form of bullying. Everything is Layton here Layton and his poetry, Layton and his views, Layton and his amour pre: the Pro outside world hardly exists. He is full of that "bouncing vulgar vitality" that George Orwell saw in Rudyard Kipling, and if he is often fatuous -- the way he constantly excuses his selfishness and bullying by Pointing to his genius eventually becomes comic -- he just as often expresses a cold, hard truth about his peers and Canadian literature in general. He isn't sentimental, and he has little self-pity; he is partly a grown-up bully-boy, partly a sluttish and self involved beauty who loves to preen, and partly an awkward man who knows the half-truth of his masks as well as anyone.