151 



Imbert (1897)— Archives d. Physiol., Ser. 9, p. 289. 

 Krause, W. (1876) — Allgemeine Anatomic. (Hanover.) 

 McDougall, W. (1897)— Jour. Anat. and Physiol., vol. 31, p. 410. 

 Merkel. F. (1872)— Arch. f. Mikr. Anat., vol. 8, p. 244. 



(1873)— Ibid, vol. 9, p. 293. 



(1881)— Ibid., vol. 19, p. 649. 

 Perez, C. (1910) — Arch. Zool. Experimentale, 44, No. 1. 

 Retzius (1881) — Biol. Untersuch. v. Retzius. 



(1890)— Ibid, neue Folge. 

 Robertson, T. B. (1909)— Quart. Jour. Exp. Physiol., vol. 2, p. 303. 

 Rollett, A. (1891)— Arch. f. Mikr. Anat., vol. 37, p. 654. 



(1891)— Denkschrif ten. d. Akad. d. Wiss. Math. Nat. CI., vol. 58, p. 4L 

 Rutherford (1897)— Jour. Anat. and Physiol., vol. 31, p. 309. 

 Schafer, E. A. (1873)— Phil. Trans., vol. 163, p. 429. 



(1891)— Proc. Roy. Soc, vol. 49, p. 280. 

 Tiegs, O. W. (1922)— Trans. Roy. Soc. S. Austr., vol. xlvi., p. 222. 



EXPLANATION OF PLATES. 



Lettering: — M.H., Movable Hyaloplasm; R.H., Residual Hyaloplasm; S., Sarcoplasm; 



Z., Krause's Membrane. 



Plate XL 



Fig. 1. Portion of uncontracted body muscle of full-grown larva of a beetle (Cnemo- 

 plites blackbiirni) in thin longitudinal section (x2000). The individual sarcomeres are clearly- 

 seen; Krause's membrane is also prominent, and its insertion on the sarcolemma is shown, 

 A small quantity of sarcoplasm is visible. 



Fig. 2. The same, in a contracted state (x2000). The "reversal" of striations, i.e.,. 

 the accumulation of the movable hyaloplasm around Krause's membrane is clearly seen, and is 

 recognizable as occurring within the fibrillae, and not outside them. 



Fig. 3. Portion of a fibrilla from same (x3400). Krause's membrane is seen projecting- 

 beyond the fibril. Around it is a minute amount of residual hyaloplasm, connected by very 

 minute streaks of hyaloplasm with the central striation (movable hyaloplasm). 



Fig. 4. The same (x3400) in a contracted state. The narrowing of the fibril towards 

 the lower end is due to its being cut slightly tangentially. 



Fig. 5. Part of leg muscle of an adult chalcid wasp (Nasonia). Note Hensen's line; 

 also the residual hyaloplasm (x2000). 



Plate XIL 



Fig. 6. Part of body muscle of mature larva of same (Nasonia). The drawing is from 

 a thin longitudinal section, taken near the insertion of the muscles upon the integument, which 

 at this stage has chitinised (x2000). The residual hyaloplasm is very clearly seen. 



Fig. 7. Parts of uncontracted sarcostyles of flying muscles from a small chalcid wasp- 

 (Nasonia) (x3400). 



A. From the middle of the muscle. 



B. The same fibril, rather nearer its point of insertion on the integument, 

 c. The same, close to its insertion on the integument. 



Fig. 8. Part of two adjacent sarcostyles from flying muscles of a Cetoneiid beetle, in 

 the contracted state. Note the accumulation of hyaloplasm around Krause's membrane. A 

 small amount of sarcoplasm is seen (x3400). 



Fig. 9. A number of uncontracted sarcostyles from flying muscle of a large wood 

 moth (xl700). Note the great spaces between the sarcostyles; also Krause's membrane con- 

 necting adjacent sarcostyles. Note also the remarkable architecture of the sarcoplasm. 



Fig. 10 Contracted fibrils from gastrocnemius of mouse (x3000). 



