Jump, a gray daughter of Ecole Etage, and Hot Ski, a daughter of Royal Ski, each won a division of the Marlboro Nursery Stakes yesterday as Bowie Race Course opened a 36-day fall meeting.

General Manager Alvin Karwacki said the attendance of 7,196 and handle of $932,376 on the day after a holiday was more than management expected.

"We've surprised ourselves," he said. "That's good business. I thought $750,000 would be a good day."

One rider was sent to the hospital by an accident stewards blamed on 16-year-old apprentice jockey Jack Kaenel. In the second race, Restless Two Timer swerved right coming out of the gate, causing a four-horse chain-reaction spill that resulted in Mary Ellen Longan, the jockey of Oncearoundthedeck, being thrown from her mount.

She was examined at the track infirmary and complained of pain around her chin, according to nurse Pat Primm. Longan was admitted to Doctor's Hospital in Lanham for observation for a possible concussion.

Kaenel's horse finished fourth and was disqualified, being placed ninth, ahead of only Oncearoundthedeck.

In the first division of the Marlboro Nursery, Jump stalked Mystical Mood and Laughing Gull, then responded strongly when roused by jockey Anthony Agnello and drew away to a three-length victory in a sparkling 1:24 for the seven furlongs over a sloppy track. She paid $11.80.

Trainer William J. Boniface, having saddled his third stakes winner in as many days, said, "I knew they had my filly to beat. She was crucified in her last race at Timonium and we knew she was ready for this."

Jockey Ken Black had a tougher time winning the second division, surviving a foul claim by Kaenel, the rider of runner-up Dynamo Dotty. Kaenel claimed that Hot Ski interfered with his mount in the stretch.

"Hot Ski is inclined to lug in and bear out when put to pressure," Black said. "She's done that before. I don't believe there was any contact today, though."

Hot Ski, trained by Del Carroll, ran the seven furlongs in 1:25 2/5 over a "good" track. She paid $6.60.