i8o 
MORPHOLOGY OF MEMBERS. 
shoot of the system is called the Sympodium or Pseud-axis. It consists, in 
Fig. 136, B, of the pieces between i and 2, 2 and 3, 3 and 4, 4 and 5 ; the weaker 
terminal portions of the respective branches i, 2, 3, &c. are bent sideways. A 
comparison of Fig. 136 C with A shows that between a sympodially developed and 
a spurious dichotomous system the only point of difference is that in the latter each 
branch produces two stronger lateral branches. If in C one of the branches is 
imagined to be suppressed alternately left and right, the form A results, which is 
then easily transformed into B. 
Sympodial systems occur in two different forms, according as the lateral 
shoots, the basal portions of which form the pseud-axis, arise always on the 
same side or on different sides of it. 
Fig. 136.— Cymose branchings represented diagrammatically ; A, B scorpioid (cicinal) cyme ; C dichasium ; D helicoid (bostry- 
choid) cyme ; the numerals indicate the order of succession of the lateral shoots which spring from one another. 
If the sympodial ramification takes place always on the same side — e. g. always 
to the right, as in Fig. 128, D, or always to the left — the whole system is called a 
Helicoid Cyme ^ or Bostryx ; if, on the other hand, each branch which continues 
the system arises alternately right and left, as in Fig. 136, A^ B, the system is 
a Scorpioid Cyme or Cicinus. If in these cases we have to do with leafy shoots 
where the leaves are arranged spirally, a more exact definition of the terms right and 
left becomes needful. It is then necessary to imagine a median plane drawn through 
^ [Some difficulty will perhaps be felt with regard to Fig. D, which stands for a helicoid cyme 
in the text, but which is also identical with the scorpioid cyme of descriptive botany, and corresponds 
to the specific name ' scorpioides'' given by Linnaeus to several plants in which it occurs. The term 
scoi-pioid was introduced by A. P. De CandoUe (Organ ographie, vol. I. p. 415), to express a unilateral 
cyme the undeveloped portion of which is usually rolled up. This is the characteristic inflorescence 
of Borraginese, amongst which Myosotis has long been distinguished as ' scorpion-grass ' on this 
account. Bravais (Ann. des Sei. Nat. 2nd ser. vol. VII. p. 197) distinguished the helicoid cyme, 
which he defined as having the successive flowers ranged in a spiral round the pseud-axis. He 
amended De Candolle's definition of the scorpioid cyme by pointing out that the flowers are in two 
rows parallel to the pseud-axis.] 
