326 Peirce . — On the Structure of the Platts tori a 
PLATE XIV. 
Fig. 13. Cross-section of haustorium (tangential section of host) showing union 
of haustorial sieve-tubes, a with large sieve-tubes S of host : AT, haustorium ; 
S, sieve-tubes of host; c, callus-plates between host and haustorial sieve-tubes, 
x 500. 
Cuscuta glomerata , Choisy. 
Fig. 14. Longitudinal section of haustorium in Impatiens Balsamina, showing 
union of haustorial tracheids and sieve-tubes with ducts and sieve-tubes of host ; 
callus-plates in red ; t, union of tracheids and tracheae by tangential walls, x 220. 
Fig. 15. Tip of haustorium penetrating mesophyll of leaf; haustorial cells red, 
host plain. X220. 
Fig. 16. Cells of tip of haustorium growing through mesophyll-cells : a, in 
optical longitudinal section ; b, c , in actual cross-section ; haustorial cells red ; 
n , nucleus ; v, vacuole ; p, chloroplastids of mesophyll-cell. x 500. 
Cuscuta epilinum , Weihe. 
Fig. 1 7. Longitudinal section of haustorium in Linum usitatissimum , showing 
union of haustorial tracheids and sieve-tubes with ducts and sieve-tubes of host : 
host brown, parasite red, callus-plates as red lines ; c, cambium ; s, sieve-tubes of 
haustorium : h, hard bast ; p , soft bast ; m, cambium ; w, wood of host, x 125. 
Cuscuta epithymum , L. 
Fig. 18. Longitudinal section of haustorium in Calluna vulgaris ; young and 
not parallel with long axis of haustorium, hence junction of haustorial and host 
tissues only partly shown ; s, sieve-tubes with (red) callus-plates, x 1 20. 
Brugmansia Zippelii , Bl. 
Fig. I. Cells of Brugmansia (in red) in phloem and medullary ray of Cissus sp. ? 
root (in brown) ; s, sieve-tubes of Cissus ; a, chain of Brugmansia-cells in contact 
with young bud, b. x 125. 
Fig. II. Much thickened cells of parasite (red) in old phloem of host (brown), 
x 2 20. 
Fig. III. Longitudinal section of Cissus- root showing chain of Brugmansia- cells 
growing in cambium : parasite red, host brown ; xylem ; c, cambium ; s, sieve- 
tube. x 125. 
PLATE XV. 
Fig. IV. Longitudinal section of Cissus- root with Brugmansia- cells going to 
xylem and phloem : parasite red, host brown ; x, xylem ; c, cambium ; s, sieve- 
tube with c', companion-cell, x 125. 
Fig. V. Cross-section of Cissus- root showing young and quite undifferentiated 
floral structure of Brugmansia in medullary ray and adjacent to a bundle ; 
/.phloem; c, cambium; x, xylem; ifc , interfascicular cambium; mr, medullary 
ray of host (brown), x 125. 
Fig. VI. Half-developed bud of Brugmansia in section, showing a swelling 
on surface of Cissus- root, x 2. 
Fig. VII. Longitudinal section of vascular bundle of Brugmansia ; callus-plates 
of sieve-tubes in red. x 1 25. 
