206 
METHODS IN PLANT HISTOLOGY 
even when the albumen has hardened sufficiently to hold the filaments firmly 
in place. 1 
Stain in safranin and gentian-violet, and mount in balsam. 
Iron-haematoxylin is recommended for paraffin sections. The sec¬ 
tions must be very thin, 5 /jl or less. “ Material killed in 2 per cent 
formalin in sea-water and gradually transferred to pure glycerin kept 
its color perfectly.” 
For material to be mounted whole, we should recommend fixing 
in 10 per cent formalin and staining in iron-alum haematoxylin. Place 
Fig. 51 .—Nemalion multifidum: A, branch showing carpogonium, c; trichogyne, t; central 
strand, m. B, somewhat older stage showing two-cell stage immediately following fertilization, e; 
carpogonial branch, b. C, branch with antheridia, a. Fixed in 10 per cent formalin and stained 
in iron-alum haematoxylin. X400. 
the material in 10 per cent glycerin until all the water is out. Mount 
in glycerin j elly. To make a mount, take a small piece of the material, 
not more than 3 or 4 mm. long, touch it to filter paper to remove as 
much of the glycerin as possible, put it into the melted glycerin 
jelly, add a round cover, and crush by tapping on the cover. The 
antheridia and procarps are in the slender filaments, and the cysto- 
carps are in the larger filaments. If several slides are to be made, 
it is a good plan to select slender, medium, and thicker filaments, 
1 James J. Wolfe, “Cytological Studies in Nemalion,” Annals of Botany, 18-607- 
630, 1904. 
