VOL. XI, NO. 3.-BOTANICAL GAZETTE—MAR. 1886. 
The Development of the Root in Botrychium ternatum. 
DOUGLAS H. CAMPBELL. 
(WITH PLATE Iv.) 
Among the peculiarities of the Ophioglossacex distinguish- 
ing them from the true ferns are the roots. hese are much less 
humerous, but of correspondingly greater size, only one root 
being developed at the base of each leaf, and consequently, in 
such forms as produce but one leaf annually, but one principal 
root is formed each year, though probably several leaves are de- 
veloped the first year, and a corresponding number of roots. On 
account of the extreme shortening of the internodes of the stem, 
Which in large specimens of the species under consideration sel- 
dom reaches a length of more than two or three centimeters, the 
roots are much crowded. 
The roots are thick and fleshy, and almost completely desti- 
tute of root-hairs, thus differing very much from most other pter- 
idophytes, the older ones being sometimes 3mm. in diameter. 
they have a thin brown epidermis in the younger parts, becom- 
Ing in the older portions thicker and wrinkled, forming with the 
underlying tissue a tough and ridged cortex. 
Arising from the larger roots are smaller ones, formed in acro- 
petal succession, but in smaller numbers than in the true ferns, 
and not as distinctly two-ranked. Nothing was observed to indi- 
cate that they arose dichotomously, or in any way differently from 
the ordinary methods in other pteridophytes. In some cases it 
was evident that a lateral root had taken the place of the main 
One, whose apex had apparently been in some way injured, and 
™ one case this had been repeated, two roots branching out the 
second time nearly at the same point, diverging widely, and at 
first sight having the appearance of dichotomous branching, but 
their lateral origin was plainly evident on closer examination. 
Pe ossibly the supposed dichotomous branching of the roots was 
derivative cells become differentiated into the permanent tissues 
of the root. The root-cap differs in appearance from that of the 
