446 BOTANICAL GAZETTE | [DECEMBER 
Two other important parasites on B. sagitiata are a nematode 
and an acarinid. The former is found in the young stem bud before 
it appears above the ground. The worm eats its way through the 
bud, mostly in epidermal and cortical tissues, leaving a dry decay 
behind. Undoubtedly this does much to sap the. vitality of the 
developing vegetative parts, if not entirely forestalling growth. 
The mite is found in the sinuses between the leaves, sucking out the 
juices at the bases of the new leaves. Several hundred were found 
at times in a single leaf bud. This parasite, too, undoubtedly 
causes serious damage to the plant and serves to control its abun- 
dance. 
Collection and preservation of material 
The material on which this study is based was collected from 
July to November 1915 and from April to June 1916. Certain 
roots, stems, and leaf buds were examined fresh, just after collec- 
tion. Freehand sections were made and observations taken from 
water mounts. Other material was allowed to dry and was _ 
examined as such. However, the greatest part of the material was 
fixed in various fluids and preserved in alcohol for more detailed 
examination. Of this last group, material fixed in acid alcohol and 
preserved in 70 per cent alcohol gave the most satisfactory results. 
Certain seedlings germinated in the laboratory, illustrating onto- 
genetic growth, were fixed in Carnoy’s fluid. In addition to free- 
hand sections of the alcoholic material, sections of typical roots 
were made 12 u thick in series and similar series of the stem and 
peduncle 8 uw thick. Sections of seedlings were cut 8 u thick. 
Various stains were tried, but the most satisfactory combination 
was acid fuchsin with malachite green counterstain. This combi- 
nation gave an excellent contrast, since the lignified hadrome and 
sclerome elements, as well as suberized walls of the Casparian strip, 
took on a copper green against the fuchsin background. The ordi- 
nary resin stains, cupric acetate and alkannin tincture, were made 
use of throughout the study. The alkannin was found extremely 
satisfactory, since it was both specific and rapid. Osmic acid fumes 
(osmic anhydride) were used to test for fats. Iodine in potassium 
iodide was employed for starch testing. Chloriodide of zinc was 
