190 



EDWARD C. JEFFREY ON THE (iENUS EQUTSETUM. 



PLATE 20. 



Fig. 1. Transverse section of a node of Equisetum limosum. c. branch; d. leaf-traces ; 6. rhizophoric organs. X25. 



Fig. 2. Tangential section of the node of E. hiemale. c. branch ; t. leaf-traces ; I. vallecular lacunae. X25. 



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



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



Fig. 5. Radial section through an aerial node of E. hiemale at the point of origin of a branch. <l. nodal diaphragm ; n. 

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



Fig. C. Radial section of a terrestrial node of E. hiemale at the point of origin of a nodal bud. 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 origin of a large vertical 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. Course 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 intemodal bundle, px. protoxylem ; mx. metaxylem ; It. leaf-trace; n. nodal wood. X200. 

 Fig. 5. 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, 1899. 



