Histological Studies in the Artemisia Formation 27 
EXPLANATION OF PLATES 
All figures were drawn with the aid of an Abbe camera lucida, using 
Bausch & Lomb microscope stand BB with objective 2/3 0.24 N. A. with 
ocular 1, except figures 35, 36, 37, 38, 39, and 40, which were drawn under a 
higher magnification by using ubjective 1/6 0.85 N. A. with the same ocu- 
All figures are drawn to the scale of 120 diameters, except figures 
35, 36, 37, 38, 39, and 40, which were drawn to the scale of 720 diameters, 
and all reduced one-half. 
far: 
Fig. 
Fig. 
OR ASE 
Piate: I 
. Artemisia tridentata from dry rocky ridge. 
. Artemisia tridentata from top of plant in full illumination. 
. Artemisia tridentata from within the bush, diffuse light. 
Artemisia tridentata from shade of spruces. 
Artemisia tridentata from open formation. 
. Artemisia tridentata from the edge of a creek bank. 
. Artemisia canadensis from a rocky slope. 
. Epidermal gland of Artemisia tridentata in four stages. 
. Epidermal hair from Artemisia tridentata showing nuclei. 
Prate II 
. Allionia linearis from the drier portions of the formation. 
. Odostemon aquifolium, a transition species. Very thick cuticle. 
. Lupinus pusillus. Thick cuticle; sponge-like storage. 
. Lappula occidentalis. Mucilage cells, thick cuticle. 
. Drymocallis fissa. Thick epidermis filled with mucilage. 
. Eriogonum flavum. Dense palisade; median storage band. 
. Gaura coccinea. Storage tissue; mucilage in epidermis. 
. Linum lewisit. Mucilage in epidermis and about bundles. 
Piate III 
. Scutellaria brittoni. Heavy cuticle. 
. Thelypodium wrightit. Cuticle; lens-shaped epidermal cells. 
. Pentstemon trichander. Rosette leaf; all palisade. 
. Pentstemon trichander. Stem leaf; palisade and sponge. 
. Atriplex cornuta. Epidermal scales; storage about bundles. 
. Atriplex canescens. Epidermal scales; bundle sheath of mucilage 
cells. 
PLate IV 
. Lupinus ammophilus. Dense palisade: storage about bundles. 
. Gutierrezia sarothrae. Storage about bundles; cuticle. 
. Aragallus sericeus. Dense epidermal hairs; cuticle, storage. 
. Lupinus parvifolius. From wet meadow; palisade and sponge. 
. Delphinium ramosum. Moist soil; storage about bundles. 
. Orthocarpus luteus. Homogeneous spongophyll. 
. Phacelia heterophylla. Mucilage in epidermis; upper cuticle. 
. Delphinium occidentale. From a rocky slide; an apparent anomaly. 
PLATE V 
. Calochortus nutallii. Thick cuticle; homogeneous sponge. 
. Chrysothamnus graveolens. From dry situation, much storage; 
corrugated cuticle, resin canals. 
. Chrysothamnus graveolens. From creek bank. 
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