This cuticle has regions which are hard and firm, forming an exoskeleton, and, between these, areas which are relatively soft and flexible.
"The Life-Story of Insects"
Geo. H. Carpenter
Now this jointed exoskeleton-an admirably formed suit of armour though it often is-has one drawback: it is not part of the insect's living tissues.
"The Life-Story of Insects"
Geo. H. Carpenter