50 
the pith of Stigmaria contained vasculae tissues, and that 
I have misrepresented him in stating that he had done so. 
I can only answer this by giving Mr. Binney’s words. “ The 
most important circumstance thus developed is the existence 
of a double system of vessels in Stigmaria, first shown by 
Goeppert, and the consequent approach in this respect to 
Diploxylon, Corda. In Diploxylon, however, the inner 
system forms a continuous cylinder, concentric Avith and in 
juxtaposition to the wedges of Avood forming the outer ; 
while in Stigmaria the same inner system is brokeji up into 
scattered bundles, apparently unsymmetrically arranged in 
the medullary axis or pith of the plant ” — Quarterly Journal 
of the Geological Society, voL 15, p. 17 — and on p. 78 of the 
same memoir, describing the specimen represented by fig. 2, 
he says, ‘‘The axis is filled with eleven or tAveh^e large 
vessels of circular or oval form,” and the same structures are 
again spoken of as “vessels” no less than six times in the 
next seventeen lines, with the further remark that “altogether 
these angular vessels remind me somewhat of the vascular 
tissue in the middle of Anabathra” — (loc. cit. p. 78). It is 
true that in two places Mr. Binney applies to these structures 
the term “utricles,” by which, I presume, he means cells, 
but such a term, applied to such tissues, is equally applicable 
to all known fibro-vascular structures, and is simply equiva- 
lent to saying that scalariform vessels have no existence. 
I have entered into these details because by promulgating 
vague and groundless doubts respecting work already care- 
fully done, Mr. Binney’s communication tends to reintroduce 
confusion into questions that have been virtually settled. 
It does this through failing to discriminate between 
things that differ. His introductory remarks refer to the 
common Stigmaria ficoides, whilst his justification of those 
remarks rests upon a plant of a very different character, and 
which I am absolutely certain is not the common form of 
Stigmaria. 
