GROUPS OF TISSUES, OR TISSUE-SYSTEMS. 43 
to tell whether the tissues belong to them or to the sur- 
rounding ground-tissues. The inner portion of the bundle 
(9, 9, t, t, Fig. 26, and s to ¢, Fig. 27) is made up of trache- 
ary tissue of several varieties; on the inner edge of this 
tracheary portion lie several spiral vessels (s, s, Fig. 27); 
next to these, on their outer side, are scalariform and pitted 
re 9 Ay _t hh 2 gh a 
BL SWS => Ss Ss 
aSeEeNeaA — 
AOS ISI AR SS 
FS A=ICNS AZ 
WalO Se! ZIoN= t= 
HSE er ics, [=a (p—~N 
HOS salon) < “Uff 
2b/ jase aa 
Walle sloN=aZes 
HWS SSI B We 
3 NS =" 
ey ~Gaiessix 
S S =; SS 
Ay NEES ae 
e B242=-e 
z Bye telS3 
o ol Ces: —\S 
= Sas S—=2— 
he enh IC | SSS = 
f| PIs < |e SEN 
= PSH foNS 
> ASME |SIZNE 
at = oS PONS 4 f 
PSCAaKeISCZI\ckK 
SS_fes) S BiS= 
262 eeiS eps 
CS aie! 5 Dice 
2 Oe > CZ) 
24} 
Fia. 27.—A longitudinal radial section of the bundle in Fig. 26. 
vessels (f,¢,9,9, Fig. 26; J,t,¢’, Fig. 27), intermingled with 
elongated cells, whose walls are pitted (A, h’, h’’, h’”’, Fig. 
27). The last-named are .clearly related to the vessels 
which surround them, and from which they differ only in 
their less diameter, and in having imperforate horizontal 
or oblique partitions. They are doubtless properly classed 
with the tracheids (see paragraph 52). 
82. On the outer side of the tracheary portion just de- 
scribed lies a mass of narrow, somewhat elongated, thin- 
