(in the structure of cross-striated muscle. 237 



Fig. 8. Leg-muscle of Forficula, contracted (vinegar, safranin). 



Fig. 9. Leg-muscle of Forficula contracted (vinegar, safranin). 



Fig. 10. Leg-muscle of Forficula after the action of vinegar, showing the more 

 central sarcomeres swollen, and irregular or lozenge-shaped. 



Fig. 11. Similar hut more regular appearance in leg-muscle of Harpalus ruficornis 

 after the action of vinegar. 



Fig. 12. A, B, portions of leg-muscle of Vespa, C, of Harpalus ruficornis, showing 

 „reticulum" (vinegar, gold, formic). 



Fig. 13. A, B, Small darkly stained isolated portions of „reticulum", showing 

 that it is really lamellar. 



Fig. 14. Leg- fibre of Harpalus ruficornis, splitting into disks (vinegar, safraidn). 



Fig. 15. Isolated disk with polyhedral network from leg-muscle of Pterostichus 

 niger. The disk has one edge turned up so as to exhibit a side view 

 (vinegar, safranin). 



Fig. 16. Isolated disk, with radial network, from leg-muscle of Harpalus ru- 

 ficornis (vinegar, gold, formic)- Part of the sarcoplasm network is deeply 

 stained. 



Fig. 17. Leg-muscle of Harpalus ruficornis, showing the transverse networks 

 alone stained by gold (vinegar, gold, formic). These appear in trans- 

 verse optical section as dark dots (a); in oblique section as short black 

 lines, b. 



Fig. 18. Part of an isolated disk of Harpalus ruficornis, showing transverse network 

 intensely stained by gold (vinegar, gold, formic). Nothing else was stained 

 at all in this specimen. 



Figs. 19 and 20. Portions of gold-stained disks of leg-muscle of Harpalus ru- 

 ficornis, with the radial sarcoplasmic lamellse somewhat separated by 

 pressure on the cover-glass. The substance between the sarcoplasmic 

 lines is seen to be subdivided by fine septa (vinegar, gold, formic). 



Fig 21. Leg-muscle of Dytiscus marginalis — osmic preparation. A, viewed with 

 light coming directly through the transverse planes. B, viewed with 

 light coming at an oblique angle to the transverse planes. 



Fig. 22. Leg-muscle of Dytiscus, osmic preparation. Teased to show apparent 

 „fibrils" • 



Fig. 23. A single „fibril" more highly magnified. 



Fig. 24. Portion of leg-muscle of wasp (Vespa vulgaris) A. alcohol preparation 

 examined in glycerine. B, the same after cautious addition of formic acid. 



Fig. 25. Wing-sarcostyles of wasp, fresh. A, moderately extended. B, somewhat 

 retracted. C, strongly retracted or contracted. 



Fig. 26. Wing-muscle of wasp; longitudinal view (vinegar, gold, formic). 



Fig. 27. Wing-muscle of wasp: transverse section (vinegar, gold, formic). 



All the remaining figures are from preparations made by the method of 

 Eollett described in the text (p. 205). 



Fig. 28. Wing-sarcostyle (Vespa) a, retracted part, b. more extended part. Magnified 

 2300 diameters. 



