That was in May. In November a cold, unseen stranger, whom the doctors called Pneumonia, stalked about the colony, touching one here and there with his icy fingers. Over on the east side this ravager strode boldly, smiting his victims by scores, but his feet trod slowly through the maze of the narrow and moss-grown "places.
This passage is from the story named "The last leaf" by O. Henry
Dose "colony" means their society?
In Longman dictionary it is "by the score" that means "in large number" but here in this context it is "by scores" -- is there any difference between them!?