190 EDWARD C. JEFFPkEY ON THE GENUS EQUISETUM. 



PLATE 29. 



Fig. 1. Transverse section of a node of Equisetum Uinosuin. c. brunch; d. leaf-t races ; /;. rliizophciric organ.s. X25. 



yig. 2. Tangential section of the node of E. hiemale. c. brancli ; t. leaf -traces ; (. valleciilar lacunae. X25. 



Fig. 3. Deep tangential section of the node of E. hiemale. c. branch ; I. vallecular lacunae. X25. 



Fig. 4. Deep tangential .section of the node of the rhizome of E. hiemale. c. a branch ; I. vallecular lacunae. X25. 



Fig. 5. Radial section through an aerial node of E. hiemale at the point of origin of a brancli. d. imdal diaphragm ; n. 

 nodal wood ; c. the branch ; r. roots ; k. nodal shoot of the branch. X25. 



Fig. 6. Radial section of a terrestrial node of E. hiemale at the point of origin of a nodal Ijud. d. nodal diaphragm ; n. 

 nodal wood ; c. nodal bud ; r. root. X25. 



PLATE 30. 



Fig. 1. Radial section of a terrestrial node of Equisetum hiemale at the point of oiigiii of a large veitical branch, d. 

 nodal diaphragm ; n. nodal wood ; c. branch ; r. root. X25. 



Fig. 2. Radial section of a node of a terrestrial branch of E. silvaticum ; lettering as in Fig. 2. X25. 



Fig. 3. Coiu'se of the bundles in the cone of E. arvense. X4. 



Fig. 4. Tangential section passing through the leaf-trace of E. hiemale and showing its mode of origin from the protoxy- 

 lem of the interuodal bundle, px. protoxylem ; mx. metaxylem ; It. leaf-trace ; n. nodal wood. X200. 



Fig. 6. Section through the nodal diaphragm of E. hiemale. X200. 



Fig. 6. The surface of a Calamite, copied from Weiss, .showing four whorls of attached leaves a nda single row of scars 

 of fallen branches. The latter have scars of fallen leaves along their lower margin. 



Printed, April, 1S99. 



