Khodophyceae 



189 





that had previously been treated with fixative; the cover was then 

 removed, and the water on the slide allowed to evaporate. The 

 gelatinous nature of the wall prevents the contents of the cell from 

 being affected by this treatment, even when the albumen has hardened 

 sufficiently to hold the filaments firmly in place." Stain in safranin 

 and gentian-violet, and mount in balsam. 



Iron-haematoxylin is recommended for paraffin sections. The 

 sections must be very thin, 

 5 fjL or less. "Material 

 killed in 2 per cent for- 

 malin in sea- water and 

 gradually transferred to 

 pure glycerin kept its color 

 perfectly." 



It seems impossible to 

 get mounts of Nemalion by 

 the Venetian turpentine 

 method. The directions 

 for Venetian turpentine, in 

 the second edition of this 

 book, were intended for 

 filamentous red algae in 

 general, but unfortunately 

 the paragraph appeared 

 under the heading, Nema- 

 lion. 



For mounting filaments 

 without sectioning, fix in 

 10 per cent formalin, stain 

 in iron-haematoxylin, also 

 stain material in Magdala 



red and anilin blue, and follow the glycerin method, as described 

 in chap. vii. When the material is ready for mounting, tease a small 

 piece on the slide with needles, add a round cover, and still further 

 dissociate the filaments by tapping on the cover. Seal with gold 

 size or some other sealing medium. 



D 



" 



FIG. 47. Batrachospermum moniliforme: from 

 a preparation stained in Mayer's haem-alum and 

 mounted in glycerin; A, portion of plant showing 

 branches and several cystocarps; X25; B, pro- 

 carpic branch showing carpogonium, p, and tricho- 

 gyne, t, with a male cell, s. attached; X255; C, a 

 younger branch showing carpogonium and tricho- 

 gyne; X255; D, branch with three male cells; 

 X255. 



