Nemalion multifidwn, Ag. 
349 
PLATE XXII. 
Vegetative Structure. 
Fig. i. Terminal cell at the apex of the thallus, nucleus in prophase, x 2,200. 
Fig. 2. Same, nucleus in later stage of prophase, x 2,200. 
Fig. 3. A cell at the apex of the thallus putting forth a bud which will develop into a side- 
branch. Metaphase of a vegetative mitosis, showing eight chromosomes, x 2,200. 
Figs. 4-6. Stages in the division of a terminal cell, showing division of the chromatophore. 
x 1,520. 
Fig. 7. Terminal cells of a central strand filament, with no sign of a chromatophore. x 2,200. 
Fig. 8. Development of the chromatophore. <2, earliest stage; b, a little later; c, d, e, develop- 
ment in an interior cell ; /, g, h , development in a terminal cell. 
Fig. 9. Mature chromatophore in a terminal cell, x 2,200. 
Fig. 10. Mature chromatophore in a cell midway between the base and the apex of a filament, 
x 2,200. 
Fig. 11. Mature chromatophore in a cell at the base of a filament, x 2,200. 
Fig. 12. Mature chromatophore in a terminal cell, the pyrenoid divided, a frequent occurrence, 
x 1,520. 
Fig. 13. Mature chromatophore in a terminal cell, showing the effect of Merkel’s fluid, the 
pyrenoid broken down, x 2,200. 
Figs. 14, 15. Mature chromatophore in a terminal cell, showing the effect of chromacetic acid, 
the pyrenoid partially or wholly destroyed, x 2,200. 
Spermatogenesis. 
Fig. 16. Metaphase at the cutting off of an antheridium. x 2,200. 
Fig. 17. Telophase and chromatophore division at the cutting off of an antheridium. x 2,200. 
Fig. 18. Prophase in the antheridium. x 3,300. 
Fig. 19. Metaphase in a spermatium which is attached to a trichogyne. x 3,300. 
Fig. 20. Male nucleus in the trichogyne. x 1,520. 
Fig. 21. A fertilized carpogonium. Two spermatia are seen. A nucleus from the lower one 
has fertilized the egg, the other nucleus is disintegrating in the lower portion of the trichogyne. 
Both nuclei belonging to the upper spermatium are visible, one still within the spermatium, the - 
other in the trichogyne. x 1,520. 
Fig. 22. Male nuclei in the trichogyne. One has broken down, x 1,520. 
Fig. 23. Male nucleus entering the carpogonium. x 1,520. 
Fig. 24. Several spermatia on one trichogyne. Male and female chromatic nucleoles fusing in 
the zygote nucleus. The carpogonium already cut off from the trichogyne. x 1,520 
PLATE XXIII. 
Oogenesis and Fertilization. 
Fig. 25. A developing procarp, x 200. 
Fig. 26. A young carpogonium and trichogyne. No trichogyne nucleus is present. It is rather 
unusual to find the nucleus above the chromatophore at this stage, x 2,200. 
Figs. 27, 28. Trichogyne nuclei. Fig. 28 shows that the trichogyne nucleus can be cut off in 
the lower portion as well as in the upper part of the carpogonium. x 1,520. 
Fig. 29. Entire procarp with immature trichogyne. A trichogyne nucleus is present in process 
of disintegration, x 1,520. 
Fig. 30. The female nucleus above the chromatophore, as the male nucleus descends in the 
trichogyne. The more usual position, x 1,520. 
Fig 3 * 3 1 , 32. Fertilization. It more usually occurs at the upper end of the carpogonium than 
in the lower portion, x 2,200. 
The Reduction Division. 
Fig- 33 * Resting zygote nucleus with delicate chromatic reticulum, x 2,200. 
Fig. 34. Early prophase. The thread system beginning to thicken and shorten, x 2,300, 
Fig. 35. Here and there knots of chromatic material have appeared, x 2,200. 
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