10 BULLETIN 795, U. S. DEPARTMENT OF AGRICULTURE. 
ers and from daisy flowers lias emphasized the need for caution in 
placing reliance upon any histological characters in the daisy flow- 
ers other than those of the achene. Other characters, with the ex- 
ception of the T-shaped hairs of the Dalmatian flowers (PL II, fig. 
3) and the crystal-bearing stone cells of the achene, are too nearly 
like similar characters in insect flowers. While these hairs and crystal- 
bearing stone cells of the achene would furnish a means of iden- 
tifying Dalmatian flowers in a mixture with other materials, they very 
apparently offer no means of discovering the presence of the daisy 
flowers when mixed with Dalmatian flowers. Thus the presence of 
this brownish-red material (PI. I, fig. 4) and the palisade-like epi- 
dermal cells (PI. IT, fig. 2) furnishes a reliable means of detecting 
even small quantities of daisy flowers in a mixture. 
No attempt has been made to describe the other parts of the daisy 
flower in detail, the scope of this paper being limited to those differ- 
entiating tissue elements which might be readily detected in an 
insect powder adulterated with powdered daisy flowers. A brief de- 
scription of the diagnostic tissues of the achenes of the Dalmatian 
flower (C. cineraria folium) and of the daisy flower (C. Leucanthe- 
mum) follows: 
Dalmatian power achene. — Characterized in the powder by rec- 
tangular patches of hard sclerenchyma tissues, strongly lignified and 
possessing numerous clinorhombic crystals which exhibit a great 
variety of colors under polarized light. In older flowers (open flowers) 
isolated stone cells are very common (PI. I, fig. 3; PI. II, fig. 1). 
Daisy flower achene. — Characterized in the powder by irregular 
dark-red fragments of variable size exhibiting a very deep-red color 
when the poAvder, after heating in chloral hydrate solution (about 
1:1), is examined under the microscope; also by closely-packed pal- 
isade-like tissue with thick walls and narrow lumina, usually present 
in radial section in the powder (PI. I, fig. I; PL II, fig. 2). 
SUMMARY. 
While there are certain differences in the chemical composition of 
Chrysanthemum cineraria folium and Chrysanthemum Leucaiithemiini, 
a chemical analysis is insufficient to show adulteration of insect pow- 
der with daisy flowers. 
Adulteration of insect powder with powdered daisy flowers can be 
definitely determined by microscopic examination. Powdered daisy 
Mowers are distinguished by (a) the irregular dark-red fragments of 
the achene, and (b) the palisade-like cells comprising the costal tissue 
of the achene. 
