1896] OPEN LETTERS 73 
original monographs. For example, the definition of bark, which is criticised, 
differs in no essential point from that given by De Bary in his text-book on 
anatomy and repeated by Vines in his text-book of botany, published in 1895. 
In fact, the same definition was given in an article on “ Cork Wings,” which 
was printed in the BOTANICAL GAZETTE in 1888, The expression objected to 
in regard to the f tion of th bi is a very common one innumerous 
German books, and its truthfulness has never before been called in question, at 
least tothe author’sknowledge. Thisisalso true of the statement made concern- 
ing monocotyledonous stems, namely, that they may change from the mono- 
to the dicotyledonous type. It is not quite so evident perhaps that the tra- 
cheids and accompanying cells may be called the assistants of the ducts and 
sieve-tubes. Even here the author can lay no claim to originality, Almost 
all modern text-books of plant physiology contain a similar statement or inti- 
mate that such is the fact. The phloem carries the prepared food about the 
plant, the sieve-tubes the insoluble, the accompanying cells the soluble por- 
tions; while whatever may be the function of the ducts it is admitted by all 
authoritative writers that the tracheids aid them in this function, or, in certain 
cases, supply the place of the ducts which are wanting. With reference to 
the “confusion regarding the elements of secondary bast,” etc., it is, perhaps, 
only necessary to say that the statements made on this subject were the result 
of the comparative study of all the leading text-books as well as numerous 
original articles, and, we may add, a modest amount of original work on the 
part of the author. The language was made as simple as possible, and it 
may be that the entire omission of the customary technical phraseology caused 
the reviewer to suppose something must be wanting. 
For one familiar with the facts of plant anatomy by years of study, not 
only of text-books but also of the plants themselves, it is hard to conceive how 
a candid critic could take exception to these statements. Indeed, if the 
author may not be considered “authority” on these subjects she has erred in 
company with the illustrious scientists of the present and past, with such men 
as Naegeli, Cramer, De Bary, Sanio, Vines, Reinke and Schwendener. 
The author heartily agrees with the reviewer in wishing the book were 
better and also in the hope that a revision, in the near future, may be made 
which will render it more useful. Emity L. Grecory, New York City. 
_ [The reviewer must call attention to the fact that as regards the “bark” 
he merely raised the question whether it was the Bore of the Germans which 
Is “commonly called bark.” He is aware that in English translations of Ger- 
ngs works this word has been translated dar, but he is unwilling to accept 
authority” on this question, with which he may deal elsewhere shortly. 
‘ As 0 the cambium ring: since the completion of the ring by the forma- 
ton of interfascicular cambium recedes the formation of secondary bundles, 
reviewer cannot understand how the ring “may be said to be formed either 
