A Lowell House senior leaped to his death from the fifth floor of a Portland, Maine, hotel early yesterday morning.

William J. Hotch of Watertown, Mass., apparently committed suicide because of depression over scholastic difficulties, according to farewell notes left in the hotel room.

His father, Arthur S. Hotch, stated however: "I don't have any idea why he did it. I didn't have any indication that it would happen. He had all A's and had won several scholarships. He must have just cracked up."

Mysterious Trip

Hotch is believed to have left Cambridge for Portland Wednesday afternoon after refusing to tell his family why he was going. He took a room in the Hotel Falmouth and proceeded to remove all identification marks from his luggage and clothing. He overlooked only a cleaner's tag inside a suit coat which proved the immediate means of identification.

In Hotch's room after his suicide, police found two notes, one to his parents and another to his roommate in Lowell House, Stephen Stamatopulos '53. They also discovered a knife and a glass containing a mixture of poisons. In one note the youth claimed he was "being laughed at and ridiculed" at school, police said.

Hotch, a 1949 cum laude graduate of Exeter, was a Classics major at Harvard.