280 General Notes. [ March, a 
i 
By this structure the formation of root-hairs by the tree is entirely 
prevented, and it is through it alone that it is able to absorb nu- 
triment out of the soil. It makes its appearance first on the lat- 
eral roots of the young seedling, and is constantly being replaced 
by fresh formations on older roots. Dr. Frank found this struc- 
ture invariably on every root examined of trees belonging to the 
Cupuliferze, also occasionally on Salicaceæ and Conifera, but 
never on woody plants belonging to other natural orders, nor on 
any herbaceous plant. It is quite independent of the nature of 
the soil. He also regards the phenomenon as an example of 
Dr. Woronin confirms these statements in relation to Conifere, 
Salicacez, and some other trees, and thinks it probable that the 
fungus, which he regards rather as truly parasitic, is a Boletus— 
A, W. Bennett. 
always found in the interior of the frustule, seems possible, except 
that they constitute a nest of embryonal diatoms on the point of 
escaping from the mother-cell. This is in accord with previous 
_ observations of the author on similar round bodies seen on the 
point of escaping from a Podosphenia, and with observations of 
Rabenhorst and O’Meara. The fact that the diatoms in which these 
bodies were observed had previously been treated with boiling 
sulphuric acid with addition of potassium chloride, shows conclu- 
sively that the round bodies seen to escape from living diatoms 
are not Infusoria or other organisms fortuitously collected round 
and demonstrates at the same time that, from the first mo- 
‘ment of their existence, diatoms must be provided with a sili- 
_ C€ous coating, though it may be of extreme tenuity. It would seem 
from these observations that diatom may assume the function 
of a sporangium, producing in its interior embryonal forms by — 
which the species is reproduced, and which ultimately acquire the 
_ form and approximately the size of the mother-frustule. 
In connection with this subject, Mr. F. Kitton states (Jour. 
_ Quekett Micros. Club) that he found on carafes of water a film 
_ composed entirely of frustules of Achnanthes linearis ; but on filt- 
_ ering the water, these were never found on the filter-paper, 2No 
_when the filter-paper was boiled in decarbonized sulphuric acid, 
m 
Aa a a er 
