260 
PROGRESS OF MICROSCOPICAL SCIENCE. 
Cienkowsky was able to observe the taking up of solid food by suction 
of algae. Thus tbe boundary lines, wbicb it has so long been usual to 
draw between plant and animal organisms, and between the individual 
groups of those lowest forms of life, appear more and more illusory, 
and the supposition is recommended of a common lowest kingdom of 
organisms, that of Protista (Haeckel), out of which animals and plants 
have by degrees been differentiated. 
The Functions of the Hairs on the Bootlets of Plants is thus ex- 
plained by Mr. B. C. Halstead, in a late number of the ' Gardener's 
Monthly.' He states that the largest portion of the liquid used by 
the growing plant makes its entrance through the roots, from the soil, 
is a well-established fact ; but those parts which are the most active 
in the absorption of this food material in solution were for a long 
time not so clearly understood. By careful experiments and micro- 
scopic investigation, it is found that the extreme tips of young roots 
are about the only portion which take little or no part in this work. 
A short distance back from the growing points, on nearly all growing 
roots, may be seen with the aid of a microscope a large number of 
minute, slender bodies, extending' out in all directions from the surface 
of the root. These thread-like structures are not inaptly called root 
hairs, and consist of sac-like protuberances, as outgrowths from the 
epidermis or surface cells of the root. With the naked eye they are 
not easily seen ; but their presence may be inferred from the manner 
in which they cling to the particles of the soil when a young root is 
lifted carefully from the earth in which it was growing. This power, 
which they have of fixing themselves to the grains of earth, is very 
great ; so that, when a plant is taken violently from the soil, large 
portions of these delicate hairs are broken from the roots, and retain 
their attachment to the soil. As the root grows along in the earth 
new hairs are produced, while those behind perish as the root 
becomes woody, and a dense, non-absorbing, protecting epidermis 
is formed ; so that the active life of a single hair is of short duration. 
The of&ce of these hairs must have already suggested itself to the 
reader. By means of these prolongations the greater part of the 
absorption takes place, though the newly-formed surface cells are also 
active. 
Microscopic Anatomy of the Oviduct of Cistudo Europcea. — The 
' Archives de Physiologic ' (No. 3, 1876) contains an important paper 
on this subject by M. F. Lataste. It records results obtained at the 
histological laboratory of the College of France. The following are 
the more valuable conclusions. He says that there are five mem- 
branes to be distinguished in passing from within outwards: (1) A 
mucous epithelium, vibratile at first, with laminsB of caliciform cells ; 
this layer diminishes in thickness from above downwards. (2) A con- 
nective layer, whose thickness goes on increasing from above down- 
wards ; without glands above, then containing glands of two kinds, 
first mucous with caliciform cells, then others of a special kind. 
(3 and 4) Two muscular layers, absent from the upper part, where 
they are replaced by smooth fibres in the midst of connective tissue ; 
