For the past month, Andrea Gail Cervantes has made family members crack their eggs at the top, not in the middle.

That's so they can fill them with confetti, decorate them and smash the eggs - called cascarones - on the heads of friends and relatives, a tradition in the Cervantes family and many other Mexican-American families for generations.The Spanish word for eggshell is cascaron, and for many Latino-American families they are an essential part of Easter celebrations.

"It's a tradition Mexicans are reared on," said Ms. Cervantes' mother, also named Andrea.

For some families, it's a yearlong project.

Judith Zaffirini, a state senator from Laredo, has been saving eggshells since last Easter.

"We collect year-round. We never stop," said Mrs. Zaffirini, who has a 7-year-old son. "I keep them in the cabinets in the kitchen. At Christmas, that's when we really collect a lot of cascarones because I make a lot of sweets.

"But this year we have fewer Easter eggs because my husband used to eat two eggs for breakfast, now he only has one."

Last year, the Zaffirini family collected more than 100 dozen eggshells.

The craft of filling the eggs with confetti and covering the shells with tissue paper can be a profitable business, especially this time of year.

Jesse Moreno, special activities coordinator for El Mercado (The Market) in San Antonio, said some vendors sell the eggs all year.

San Antonio residents not only purchase cascarones for Easter celebrations, they also stockpile them for Fiesta, a weeklong, citywide celebration of parades and parties after Easter.

Vendors along the Texas border with Mexico sell cascarones by the bag, with customers able to get 100 for about $1.50.

Stories of cascarones' origination vary, but all seem to tie it to Europe.

A 1980 brochure published by the Conservation Society in San Antonio said perfume-filled eggshells were used in Italy during the Renaissance. According to that account, Carlotta, wife of Maximillian, an Austrian duke who established an empire in Mexico for Napoleon III, brought them with her to Mexico.

Moreno said perfume-filled cascarones were brought to Italy from China by Marco Polo. They eventually made their way into Spain and then to Mexico. Somewhere along the line, the perfume was replaced with confetti, he said.

The empty eggshell is said to symbolize the empty tomb of Jesus Christ. The colorful confetti is a reminder of the joy of the Christian belief in Christ's resurrection.

The cascarones are the center of many celebrations such as birthdays, weddings and even Christmas, but are most important at Easter. Families often color and fill the shells together.

Like hard-boiled Easter eggs, cascarones are placed in baskets or hidden. But often, the eggs are carried to a picnic spot in a park where children and adults try to sneak up and smash the eggs on each others' heads.

"I sit down with the kids and we paint and decorate them. It's a lot of fun and we can share a moment or two and do things together," said Eddie Lucio, a state representative from Brownsville, who says he also made cascarones as a youngster.

"We do get together and set out some ground rules, and rule No. 1 is not to get mad. Rule No. 2 is not to hurt anybody and rule No. 3 is to clean up the mess," Lucio said.