Hundreds of undergraduates suddenly began vomiting last night. Officials at University Health Services (UHS) struggled into the morning to treat the ill, while speculating that the cause was food poisoning.

UHS was besieged by close to 200 students, according to director Dr. David S. Rosenthal '59. Rosenthal said the undergraduates were suffering from "acute initial nausea and vomiting."

"This is a first for me," Rosenthal said. "A great number of students have been admitted for observation." Asked if any students were in serious danger, the doctor said: "Fortunately, not."

Rosenthal found out about the epidemic when he made a routine call to the clinic at 7 p.m. By midnight, five physicians, including the director himself, were staffing the emergency desk, and nurses were working double shifts. At 2:45 a.m., Harvard police were sent to Mt. Auburn Hospital for additional supplies of medication.

Students will likely remain ill for only 24 hours, Rosenthal said.

At midnight, harried staff members were asking students to stay home and drink water even as new arrivals flooded the already-crowded waiting rooms.

Scores of other students chose not to go to UHS or were turned away.

Most of the victims were first-years, but some members of the upper classes were also among the ill. The sick included those who ate at the Freshman Union and a handful of students who ate at the house dining halls.

The epidemic's cause could not be immediately determined. Friends and roommates of ailing students offered theories ranging from an errant Chemistry 10 bacillus to the fusilli in the Union's salad bar.

In dozens of interviews with sick students last night, no common denominator emerged as a possible source of the illness.

In fact, the only thing stricken students have in common is their nausea. Asked how he felt, one first-year responded: "Like shit."

In the lobby of the UHS night entrance under Holyoke Center, several students were slumped on couches with pink plastic basins placed next to them to catch their vomit.

Others were collapsed on the floor, barely appearing to breathe. As a nurse moved from one body to the next, a student stumbled in from the waiting room and crumpled to the carpet, clutching his own bowl next to him.

A security guard stepped over the prostrate figures to empty basins from sick students into the storm drain in the driveway.

"Looks like Logan airport in here," the guard said.

A number of administrators--including Associate Dean of Freshmen W.C. Burriss Young '55 and proctor Keith W. Light--showed up at UHS to comfort the afflicted, according to Rosenthal.