A CLASS LIST OF PREPARATIONS 
321 
3. Bacillus anthracis. —In liver of mouse. Paraffin sections, 5 p. Stain 
in gentian-violet, Gram’s method. 
4. Oscillatoria. —Fix in special chromo-acetic-osmic acid and stain in iron- 
alum haematoxylin to show nuclei. Venetian turpentine method. 
5. Tolypothrix. —Use the Venetian turpentine method. Should show 
heterocysts, hormogonia, and false branching. 
6. Nostoc. —Venetian turpentine method. 
7. Wasserblicthe: —The principal forms in this material are: 
a) Coelosphaerium Kutzingianum. —Colonies in the form of hollow 
spheres. 
b) Anabaena gigantea. —Filaments straight. Preparations should show 
vegetative cells, heterocysts, hormogonia, and spores. 
c) Anabaena flos-aquae .—Filaments curved. Stain on the slide and 
mount in balsam. If material is abundant, stain in iron-alum 
haematoxylin and mount in Venetian turpentine. 
8. Gloeotrichia. —Smear on the slide, stain in safranin and gentian-violet, 
and mount in balsam; or use the Venetian turpentine method, staining 
in Magdala red and anilin blue and crushing under the cover-glass. 
ALGAE 
CHLOROPHYCEAE 
9. Volvox. —Use the Venetian turpentine method. If paraffin material 
is available, cut 5p in thickness and stain in safranin, gentian-violet, 
orange. 
10. Scenedesmus. —Let a drop containing the material dry upon the slide 
stain, and mount in balsam. 
11. Hydrodictyon. —Use the Venetian turpentine method. 
Each preparation should contain pieces of old and of young nets, and 
also at least one young net developing within an older segment. The 
greatest care must be taken not to injure the older segments while arran¬ 
ging the mount. 
12. Ulothrix. —Use the Venetian turpentine method. Each mount should 
show various stages in the development of spores and gametes. 
13. Oedogonium .—Stain in Magdala red and anilin blue and mount in 
Venetian turpentine. 
14. Coleochaete. —Stain in Delafield’s haematoxylin and mount in balsam. 
15. Cladophora. —Stain some in iron-haematoxylin and some in Magdala 
red and anilin blue. Mount both together in Venetian turpentine. 
16. Diatoms. —Make mounts of the frustules and also stained preparations 
showing the cell contents. 
17. Desmids. —Make mounts of available forms. Use the Venetian turpen¬ 
tine method if material is sufficiently abundant. 
