In 1963, Nathan Perlmutter wrote a book and titled it "How to Win Monty at the Races" (MacMillan Co. and still in print). Late this afternoon he validated it. Ruthie's Native, the horse he bought for his wife's one-horst stable, won $69,900, beating everything else in the second division of the Florida Derby at Gulfstream Park.

It was a two-part Derby, due to the 18 entries, and the first division also saw the favorite beaten when the 6-to-1 shot, Coined Silver, whooshed past the leaders in the stretch to project his name into future Kentucky Derby consideration, as did Ruthie's Native.

The second division of the race was the slow one, at 1:50 1/5 ran nearly four seconds off the local record for the 1/16 miles, but it had mora romanticcaspects. Whereas Coined Silved, winner of thefirst division, is owned by C. V. Whitney, of racing's elite, the Perlmutters are new to stakes socitty.

When he isn't writing books on how to beat the races, Perlmutter has the unlikely rule of assistant national director of the Jewish Anti-Defamation League. Mrs. Perlmutter is a former professor of philosophy and criminology at the University of Miami. They now reside in New York.

Mrs.Perlutter was also striking a blow for antipoverty with her winnings today. She was formerly a director ox the antipoverty program of the Economic Cooperation Office in New York.

The Whitneey's it was observed here, never had to fight poverty, expect in their philanthropic endeavers.

Until the results were in, this Florida Derby had been looming as the LRoy Jolley caper. That trainer entered five horses in the two divisions, in a frontal attack on both winning purses. But the Jolley plan began to dissolve early this morning when he scratched two of his steeds, the longshots Dept Finier and Solly, out of the first division. This left a somewhat clearer path for his mother's horse, nearly On Time, which went to the post the second choice to Fort Prevel.

The upshot was that Jolley ran second in both heats. Nearly on Time faltered after leading the first division all the way around the track and was overtaken by Coined Silver's late rush.

In the second division, Jolley was represented by the favorite. For The Moment, and 13-to-1 shot Mr. Red Sing. For the Moment set out after Ruthie's Native in the early rushing and faltered by the margin of a neck in the final rush to the wire.

Ruthie's Native's victory was recompense for jockey Craig Perrett, who had finished second with Nearly On Time in Group One. He sent the winner out on the lead in a slow pace and with Mickey Solomone and For The Moment eying him grimly from second for the first six furlongs, Perret made a bright move. He called for some big jumps from Ruthie's Native as they turned for home, stretched a half-length lead into two lengths, and it was that margin that served him well when For The Moment was getting to him in the final strides.

They were bunched like fingers coming into the wire, but at the finish it was Ruthie's Native in front by a neck with For The Moment a neck in front of the challenging third choice, Sir Sir.

Oddly, it was the supposedly weaker first division of the race that turned in the faster time,1:48 1/4 for the 1/16 miles. Buck Thornburg, who got Coined Silver home for the Whitney people, said he wasn't too alarmed when the two favorities, Nearly On Time and Fort Prevel, went after each other in the first mile.

"I always had plenty of horse under me," Thornburg said, and he was content to go to the outside, turning for home. Nearly On Time carried Fort Prevel out, probably, between the eighth and sixteenth pole, and even put Coined Silver in some close quarters, but the reserve energy of the winner prevailed. Another surprise of the race is that day they didn't take down the number of Nearly On Time, and left him in second place.

Ruthie's Native paid $6.80, $3.60, and $2.80. For The Moment returned $3.20 and $2.40 and Sir Sir paid $2.80 for show.

Coined Silver paid $14, $6.40 and $3.60. Nearly On Time paid $4.40 and $3.20 and J. L. Levesque's Fort Prevel, ridden by Jeffrey Fell, was worth $2.60 for third place.