WE TRY TO KEEP UP with cultural trends, especially when trends appear to be at the ends of their tether. So we noted with as much interest as sadness the death last week of Mister Ed. Mister Ed was the famous talking horse of television in the 1960s. He passed on in Tahlequah, Okla., at the age of 33, and, as the obituary we read reported, "was buried without ceremony in a small plot."

The plot, of course, could not have been all that small; and the absence of ceremony for a superannuated star is typically cruel, and hardly surprising. What is noteworthy about Mister Ed's demise is that it serves as a reminder that the age of the talking animal is gone, at least from movies and television, perhaps forever. Francis the talking mule was as popular in the 1950s as was Mister Ed a decade later. But his heyday is long past now, as is the day of Cleo the talking basset hound, of television's "The People's Choice."

What the phasing out of talking animals signifies in historical terms is beyond our reach. It may be simply that human actors protested against continually being upstaged by animals, since Cleo, Francis and Ed were not only given the best lines, but were clearly characterized as the brightest members of their casts. If this is so, it may explain why we are now in the middle of an animal backlash, in which animals are no longer portrayed as wise and lovable, but rather as "Jaws," "The Killer Bees" and "Orka the Killer Whale."

The backlash against Mister Ed was certainly swift enough. After his TV success -- the obituary noted -- he made several Western movies, "but never again had a speaking role."