fascicle

A bundle or cluster.

A bundle of skeletal muscle fibers surrounded by connective tissue.

A cluster of flowers or leaves, such as the bundles of the thin leaves (or needles) of pines.

A discrete bundle of vascular tissue.

A discrete section of a book issued or published separately, generally as a temporary measure while the work is in progress.

The OED [Oxford English Dictionary] was initially published in a series of 125 slim fascicles between the years 1884 and 1928. The first complete edition in ten volumes was published in 1928.

I was inspired to prepare fascicles like this by the example of Charles Dickens, who issued his novels in serial form; he published a dozen installments of Oliver Twist before having any idea what would become of Bill Sikes!