Viallanes. Histologie et Développement des Insectes. Ann. Sci. Nat., Zool., Tom. XIV. (1882).
Kühne in Stricker’s Histology, Vol. I., chap. v.
Plateau. Various Memoirs in Bull. Acad. Roy. de Belgique (1865, 1866, 1883, 1884). [Relative and Absolute Muscular Force.]
Leydig. Zum feineren Bau der Arthropoden. Müller’s Archiv., 1855.
Weismann. Ueber zwei Typen contractilen Gewebes, &c. Zeits. für ration. Medicin. Bd. XV. (1862).
Structure of Insect Muscles.
The muscles of the Cockroach, when quite fresh, appear semi-transparent and colourless. If subjected to pressure or strain they are found to be extremely tender. Alcohol hardens and contracts them, while it renders them opaque and brittle.
The minute structure of the voluntary or striped muscular fibres of Vertebrates is described in common text-books.[84] Each fibre is invested by a transparent elastic sheath, the sarcolemma, and the space within the sarcolemma is subdivided by transverse membranes into a series of compartments. The compartments are nearly filled by as many contractile discs, broad, doubly refractive plates, which are further divisible into prismatic columns, the sarcous elements, each being as long as the contractile disc. Successive sarcous elements, continued from one compartment to another, form the primitive fibrils of the muscle. In cross-section the fibrils appear as polygonal areas bounded by bright lines. Outside the fibres, but within the sarcolemma, are nuclei, imbedded in the protoplasm, or living and formative element of the tissue.