INSECT POWDER 21 
The Persian (186) or Caucasian insect flowers (Chrysanthemum 
roseum) differ somewhat from the Dalmatian flowers, and will be 
but briefly described. The flower heads somewhat resemble those 
of the Dalmatian variety, but are a little smaller. Ray florets, a 
reddish-purple tinge; involucral scales, dark and with reddish-brown 
edge. Fruits usually 10-ribbed. Involucre not as hairy as that of 
the Dalmatian flower. 
SUMMARY 
Dalmatian flowers.—Involucre: Imbricate and campanulate; scales 
matted with hairs; individual bracts slightly thickened or keeled, the 
inner bracts becoming thinner and more chaffy or scarious at the 
margin. 
Ligulate florets: Yellowish-white or a light straw color; pistil- 
late; apex 3-toothed, the middle tooth usually beimg shorter than 
the other two. 
Disk florets: Perfect, deeply 5-toothed, and yellowish. 
Achenes of ligulate florets: Distinctly 5-ribbed; rather more flat- 
tened and curved than achenes of disk florets and somewhat larger; 
possess small-toothed crown. 
Achenes of disk florets: Distinctly 5-ribbed; not as curved or flat- 
tened as those of the ligulate florets; somewhat smaller; possess 
small-toothed crown. 
Persian flowers.—Involucre: Imbricate and campanulate; scales 
almost glabrous; hairs numerous in depression at juncture of peduncle 
and receptacle; scales dark and bordered by a distinctly reddish-brown 
edge; inner scales more scarious than outer ones; appear to be more 
densely fibrous than those of the Dalmatian flower. 
Ligulate florets: Tinged a rather purplish-red; pistillate; apex 3- 
toothed, middle tooth often somewhat longer than the other two. 
Disk florets: Perfect, deeply 5-tcothed. 
Achenes of ligulate florets: Usually 10-ribbed; more flattened and 
curved than achenes of disk florets and somewhat larger. 
Achenes of disk florets: Usually 10-ribbed; not as curved or flat- 
tened as those of the ligulate florets; somewhat smaller. 
MicroscopicaL CHARACTERISTICS OF INSECT POWDER 
Before taking up the general plan followed by the writers in the 
microscopical examination of a commercial powder, the most impor- 
tant work done by other investigators will be reviewed briefly. 
Collin (47) has condensed the descriptions of the diagnostic charac- 
ters for the various parts of the flower head of Chrysanthemum cine- 
ranizfoivum, which may be summarized as follows: 
Fragments of the bracts: Epidermis striated and provided with numerous 
stomata, T-shaped hairs, and oil glands; under the epidermis of the central 
part there is a very characteristic fibrous hypoderma; the margins are very thin, 
and bear numerous T-shaped hairs. 
Corolla of the ligulate fiorets: Upper (inner) epidermis characterized by being 
papillose over the whole surface, and by the sinuous striated cells of the lower 
(outer) epidermis. 
Corolla of the tubular florets: Epidermis papillose near the apex but smooth 
over the remainder of the corolla, the latter portion consisting of regular cells 
containing rosette crystais of calcium oxalate. 
Calyx of the tubular florets: Tissue of the calyx strengthened by the presence 
of numerous elongated, lignified cells. At the junction of the calyx with the 
ovary there is a disk composed of large, very irregular cells, with thick, lignified, 
pitted walls. Many of these cells contain prismatic crystals of calcium oxalate, 
one in each cell. 
