RHODOPHYCEAE 



249 



Stain in safranin and gentian violet, and mount in balsam. 



Material killed in 2 per cent formalin in sea water and gradually 

 transferred to glycerin keeps its color. 



For material to be mounted whole, we should recommend fixing in 

 10 per cent formalin and staining in iron-alum haematoxylin. Place 

 the material in 10 per cent glycerin until all the water is out. Mount in 

 glycerin jell3\ 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 



Fig. 62. — Nemalion multifi'ium: 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. 



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 cystocarps are in the 

 larger filaments. If several slides are to be made, it is a good plan to 

 select slender, medium, and thicker filaments, remove the surface glyc- 

 erin with filter paper, and then crush the filaments between two slides. 

 There is scarcely any danger of crushing too much. A httle of the 

 crushed material, including the various stages, can be put into the 

 melted glycerin jelly. Add a round cover, tap gently until the jelly 

 comes just exactly to the edge of the cover. As soon as the jelly is cool, 



