of the Anatomy of the Genus Selaginella , Sfir. 147 
cuticularized endodermal cells and certain layers of the inner 
cortex. Strasburger ( 24 ) describes the vascular cylinder as 
enclosed by one or two layers of cells which stand in place 
of the pericycle but actually belong to the rind. He goes on 
to say (/. c. p. 457): ‘ Alle diese Schichten (pericycle and 
endodermis) und auch noch die nach aussen folgende, welche 
die Trabeculae ausserhalb der Endodermis aufbaut, sind auf 
die Theilung der urspriinglich innersten Rindenschicht, des 
Phleoterma, zuruckzufiihren.’ He adds, c ich hatte keinen 
Grund, die inzwischen erschienenen Angaben von Vladescu 
anzuzweifeln/ As I am not prepared to express a per- 
sonal opinion on the developmental origin of these layers, 
although, like Strasburger, I have no ground for doubting 
Vladescu’s results, I have retained the terms { pericycle/ &c. 
with the following explanation. By endodermal cells I mean 
the cuticularized cells which arise from the chlorophyllaceous 
layer surrounding the phloem, and use the term trabecida in 
a general sense for the uni- or multi-cellular strands which 
anchor the vascular cords to the cortex. The trabecula is 
sometimes merely an endodermal cell ; at other times one, 
two, or more parenchymatous cells are connected with the 
endodermal cell to form the trabecula. Similarly I retain 
the name pericycle for the green, externally cuticularized layer 
(or layers) which give origin to the endodermal cells on the 
one hand and enclose the phloem on the other. For the 
semi- or wholly occluded bright-walled elements occurring 
immediately within the pericycle I have retained Russow’s 
term protophloem . The parenchymatous layer next the 
xylem is the next point on which explanation is necessary. 
For this tissue I have adopted the name phloem-parenchyma , 
without expressing any opinion as to its developmental 
origin. 
The final point on which I wish to make an explanation is 
with regard to the use of the terms ‘ vascular bundle 9 and 
‘ stele.’ I use the term vascidar bundle to indicate a leaf-trace 
only, and retain the term stele for the vascular strand, 
enclosed within a pericycle and endodermis (using these 
