168 BOTANICAL GAZETTE [MARCH 
floral or vegetative shoots. Very frequently some very long and purely 
vegetative shoots are to be observed in mature specimens, and from 
these develop lateral (axillary) floral shoots, which generally are quite 
short and bear only a few pairs of leaves, very often only two, though 
four or five are not uncommon. Whether the vegetative shoots stay 
as ‘‘vegetative,” the ramification thus being monopodial, I am not 
in a position to state. As a matter of fact, it seems very difficult to 
make out the ramification of Mitchella, even where it occurs in 
abundance. The difficulty lies in the fact that the younger stages 
are hard to find and the adult specimens always appear as if they 
were not entirely complete. Injury to the shoots, for instance, might 
be the cause of arresting the buds in their farther and normal develop- 
ment. 
The shoots of Mitchella, however, appear to be somewhat.uniform, 
since their foliage is identical; and not as in Linnaea, where small, 
scale-like leaves occur, and the over-wintering buds are of two kinds. 
The ramification of Linnaea is doubtless much more complicated 
than that of Mitchella, but nevertheless it would be interesting to 
know exactly the behavior of the latter, how the shoots develop in 
young individuals, and especially how soon the stem becomes creep- 
ing.° 
The roots. secondary roots are relatively short, but they 
ramify freely, and they remain active for several years. They are 
hairy and possess an exodermis of the same structure as epidermis. 
The cortical parenchyma is compact and consists of about three 
strata with the cell walls moderately thickened throughout; the 
endodermis, on the other hand, is thin-walled and small-celled; cells 
° Professor Witrrock has presented a most excellent sketch of the biology of 
Linnaea borealis in Botaniska Notiser (1878-79), and calls attention to the fact that 
the earliest stages are yet unknown. In order to comprehend fully the morphology 
of Linnaea the eens questions must be answered: (1) When does the main stem 
become decumbent ? s the main stem a direct continuation of the primary axis, 
or is it developed from an axillary bud? (3) How soon does the ramification begin ? 
(4) When does it commence to bloom ? (5) Does the primary root stay unbranched, 
and how does it remain active ? (6) When do the secondary roots develop ? These 
questions may apply to Mitchella also, and I may at the same time quote another 
paper on Linnaea by Dr. SERNANDER (Bot. Not. 1891:225), in which these questions 
have been discussed and several additional observations recorded. (See also ARE- 
ScHOUG Bot. Not. 1879:1 
