14 The Botanical Gazette. [January, 
roots of Vallisneria spiralis he found an intermediate form 
between the two types. He agrees with Russow that the 7 
root must be studied in all stages of development before we ~ 
can arrive at safe conclusions. | 
Flahault says of Halle’s paper that it furnished important ~ 
conclusions, but that the number of species studied were to 
general types of meristem structure for the roots of angio- 
sperms. 
In 1877 De Bary?* made a résumé of the work accom 
plished on the meristem of roots. After discussing th 
work of various authors he asks, “If the organization of t 
different systems of tissues, and the structure of the organs 
ought to be considered as connected with the organization 0 
the terminal meristem, and also if each tissue always take 
its birth in the same part of the primary meristem.” Afte 
reviewing the principal modifications of the structure of th 
vegetative point of the root, he says, ‘‘Determined zones 0 
meristem are not always to be considered as the origin of d 
termined tissues, although it might be so in many cases.” 
While the résumé which we have made shows us that mucl 
has been done in investigating the structure of the vegeta 
tive point of roots, it also shows us that there is much cot 
fusion as to the types of structure which should be rec 
nized, which confusion can only be cleared up by a careful 
that study the following résumé of work already done on 
roots of this order may be found useful. 
23Vergleich. Anat. der Vegetationsorgane, etc. 
