506 Wisconsin Academy of Sciences, Arts, and Letters. 
EXPLANATION OF PLATE XXXV. 
Fig. 11. Longitudinal section of same, str., strands passing through 
the center. D., distal; M., median, and P., proximal por¬ 
tions. Just below the center the massing of the cells is 
shown and their gradual decrease in size. X 300. 
Fig. 12. Dorsal view showing the tracheal system and the two pairs 
of sacs which are dotted, a., mesothoracic stigmata; b, 
metathoracic stigmata; c, d, e., the three pairs of abdominal 
stigmata, f., stigmata on caudal filaments, tr., 1, trachea 
to head; tr., 2, to front pair of legs, tr., 3, to intestine, 
tr., 4, to reproductive organs. tr., 5, trachea, the upper 
branch of which goes to the fat body, the lower branch to 
the intestine, tr., 6, to intestine. X 3. 
Fig. 13. S. 0. Cl., supra-oesophageal ganglion. I. O. G., infra-oesopha- 
geai ganglion. T. G„ thoracic ganglion. P., prothorax. Me., 
mesothorax. Mt., inetathorax. Ov., where ovary passes be¬ 
tween main nerve trunk and the largest branch. X 3. 
Fig. 14. Horizontal section of thoracic ganglion, showing the three 
ganglia of which it is composed and the principal nerves 
arising from it. A., anterior. B., posterior. X 46. 
Fig. 15. Terminal joint of antenna showing sense-organs. X 92. 
Fig. 16. Single sense organ. X 630. 
Fig. 17. Male reproductive organs. T., testes. V. D., vas deferens. 
S. V., seminal vesicles. D. J., ejaculatory duct. X 2. 
Fig. 18. Testis. F., basal portion of seminal follicle. V. D., vas def- 
X 26. 
erens. 
