One student attacker was later turned in by his mother and has been suspended for 10 days, Farley said. He faces expulsion.
District officials know the identity of the other two students involved in the attack and are trying to contact their parents, she said. Those students were not in school yesterday.
The assault came just two days after a Beeber Middle School teacher reported that a 12-year-old tried to rape her in her classroom during an after-school program. The teacher said she fended off the attack and the student was arrested.
The attacks, two days apart, have once again heightened worries about supervision and safety in the Philadelphia School District.
"When there are one or two incidents like this, it raises concerns among all of the faculty about the potential for violence against staff, students and teachers," said Barbara Goodman, a spokeswoman for the Philadelphia Federation of Teachers.
"We believe that schools should be the safest place for children and for the staff and faculty. We will be pursuing this to be sure that policies are in place to prevent a repeat of this week."
Goodman praised the administrations at Germantown and Beeber for handling the situations well and meting out swift punishment.
"In both of these cases, they took the right steps. They're sending the right messages to the students that this isn't going to be tolerated," she said.
Farley, in turn, praised the student's mother who learned of the assault on Wednesday afternoon and brought her son back into school to disclose his involvement to administrators.
"You have to give credit to the mother for coming to school with her son. It's not an easy thing to do, and her son faces serious consequences," Farley said.
Laurence Dempster, Germantown High's acting principal, offered to answer questions for the staff after school yesterday.
The assault evoked chilling memories of an attack at Germantown High in February 2007 in which teacher Frank Burd's neck was broken.
One of the students who assaulted Burd that day was a special-education student. Some of the students involved in Wednesday's attack also were special-needs students, officials said.
Doe sought treatment at a local health facility on Wednesday and was cleared to return to work, Farley said. He came to school yesterday to file a report on the incident, and plans to begin teaching again today, she said.
City police have been notified of the assault, Farley said.
Germantown High has been plagued by principal turnover and, this year, community anger that Michael Silverman, the principal last year, was taken out of the school.
Silverman, credited with restoring order to Germantown, was promoted to a central office job. Earlier this year, superintendent Arlene Ackerman said she had made a mistake in removing Silverman before she had a permanent replacement in place.
Many students began the school year with no rosters, resulting in students wandering the hallways and leaving school.
But staff members said yesterday that things had been going better since then.
Contact staff writer Susan Snyder at 215-854-4693 or firstname.lastname@example.org.
Inquirer staff writers Kristen Graham and Martha Woodall contributed to this article.