Undeveloped cotton fibers are produced by seed whose development was interrupted before maturity (motes). These fibers may be considered immature, but are different from fibers commonly called immature in that they are composed only of a cuticle and primary wall. Little or no secondary layers are present. Because of their extremely thin walls, underdeveloped fibers have no structural rigidity, and collapse upon each other forming masses that are difficult to separate. Many of these adhering masses are sticky and also adhere to other materials during processing. Therefore, not only are the fiber bundles themselves a problem because they do not blend or parallelize with other fibers during processing, they also can form gummy deposits on processing equipment. Additionally, the very low cellulose content of the fibers causes them to be unreceptive to cellulose dyes, thus producing the "white spot" problem common in dyed textiles. Structures of undeveloped fibers have been examined microscopically, and their presence in undyed masses on the surface of dyed fabrics has been shown.