132 Scientific Intelligence. 
rightly understand it, the stem of a Cycas or a Cereus should exhibit — 
the endogenous and a corn-stalk or asparagus-shoot ne exogenous, 
structure. But this 1 is not the place to discuss the questio s 
The vitality of an erroneous statement is truly dondertid: A century 
ago Adanson published his account of the great Baobab trees of Sene- 
was pointed out eleven years ago, b sh late writer (in the Nort 
American Review for July 1844): nevertheless the current statement 
__ ity or pretension. Prof. Darby has now ona it with an addition 
which caps the climax of absurdity. He says siedueiiiakd copying 
ae work, we know not what one :— 
emark able case of the deposition of external layers of dicoty- 
ledonous stems is iigeis'ed of the Baobab-tree Rpepsartenes digitata) 
and 0 w cut his 1 
ined the same trees, and fo uad the names with more than 300 layers 
of wood deposited over them, gh) 
We had long ago shown that Ad 
any such thing, and that the current accoun 
ver ee to have found 
ng this was arte 
> prese 
in 
part of the ehenieanh. century, and who S was never out 
England in his life, is said to have cut his name upon two Baobab-t 
at the Cape de Verde Islands in the year 1400! 
The old notion of spongioles at the extremities of root on 
which have no existence as described—is adopted on p. 39: but in the 
description they are confounded with the root-hairs, which are not the 
sengie'e of De Candolle, nor are they * composed of lax cellular tis- 
sue,” ane only definite and free portions of superficial cells prolonged 
into S. 
So far from the origin of adventitious buds having “ completely 
eluded the research of philosophers,” no part of organogeny is better 
known. The facts of the case are to be found however, not 1 n the 
tatement that the leaves of Pines, &c., “‘do not forma single 
Spire afte ta compound one, consisting ot three or four spires running 
parallel to each other,” shows that the writer has not discriminated be- — 
tween the real spiral on which the leaves are ee and the apr 
parent or secondary spirals ee a at conspicu- 
ous when the leaves are approximated. A moment’s perant to the 
subject would enable Prof. Darby . express aa elementary facts is of 
phyllotaxis both correctly and clea A 
The fall of the leaf by an sstinielasion has surely been much better 
explained by investigations of the facts of the case, _ no - ans | 
