Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-08-21
THE BIOLOGICAL SECTION.
Several Very Interesting rap-rs Read b,
MEMBER Hi. Morning.

ssae<ss W. ~ efntu8-
Apaper entitled Movements Of Fluids in
Plants" was read by Prof. Vim. J. Beal Of Mich
igan in the biological section today. His tAlk
showed that it has been proved that fluids in
the higher plants move through the cavities OF
the cells, passing through small holes and not
through the substance Of the walls Of the cells.
IL the cavities at the end Of . stem be filed
with gelatin and then freshly cut no fluid can
be forced through the stem.
Fluids enter plants through the action Of
osmose. and within plants move from place 10
place through the action Of moee and cspil-
larity. The former is the moving force, the
latter the supporting force. There 10 q certain
periodicity Of these processes produced by
metaoolism and other causes which keep fluids
moving.
GASES IN fIASrs-
DR.. ]. c. Arthur of Purdue University, La
fayette, Ind, read paper entitled ''Gases In
Plants, saying that the history Of the discov-
cry OF gases In plants, their kinds sources and
movements was traced from the time Of NAL
pighi, 1911. TO the present day. The most val
liable part OF our knowledge Of the subject has
been derived from the Investigations Of the
last twenty-five years or even less. The gases
inside OF plants are oxygen. carbon diox-
ide and nitrogen. and the two former
only vary much. The variation is chiefly due
10 the breathing and 20 the assimilation OF
piants- Plants assimilate only in the light and
IN the part OF the plant that is green. They
breathe throughout the whole plant-roots.
stems and leaves-and the gases pass out and
into the plant through the general surface,
whether it Is covered with bark or ordinary
epidermis. The TRANSMISSION is not confined 10
the breathing pores, but takes place through
the solid walls. But while gas viii thus slowly
oinuse through cork aud other plant cover
ings, n cannot be forced through by pressure,
however great or prolonged The Law. gov
s sg the movement of gases through the diff
Iereht parts OF plants were stated, 90 far
they have been investigated. and the lines FOG
further study were pointed out
ABSORPTION OF FLUIDS BY PLANTS
One OF the interesting papers read before the
biological section was read by Prof L. " Pam
mel OF Ames, Iowa, on the Absorption Of Flu
Ids by Plants" The subject was considered
nrst ms 10 the relation soil has 10 the amount OF
water Il contains All SOILS have the power OF
absorbing more or less Of water. This dep. nds
largely on the character Of the soil. sandy
soils sbsorbs less than clay soil The
ash constituents Of plants are also alb
sorbed by the soil. This may be chemical
as well as physical. The principal ash con-
su,uents OF plants are potash, IRON, sulphur,
lime, magnesium and chlorine. The plant cam
not get along without these elements. Nitro
gen Is supplied to plants In the form of nj
trates. Though the air contains a great deal %
this important element, most plants cannot ap-
propriate this free nitrogen.
The nitrogen found in organic bodies il
changed into ammonia and nitric acid by small
living plants. so-called bacteria In a steril-
lied soil nitric acid cannot form The manner
OF absorption of fluids differ with different
plants. In some aquatics roots are poorly de-
veloped; the root hairs are absent In come
plants the leaf develops root Lsirs.
In most plants growing in soil the root sys-
tenn Is very copious and root hsirs are
abundantly developed. In certain colorless
soprophytes, like Indian pipe, the roots are
infested with a fungus. which takes up the
nourishment from the humus for the Indian
pipe and IN turn the Indian pipe nourishes the
fungus. This has been called synebiosis.
BIOLOGY OF rHE cHALcrpDE
1.-THE Biology of the Chalcidida," by L. O.
Howard Of Washington, ID. C., was Q contribu-
ton to the question of parasitism among in
sects. The chalcidida form the largest family
of parasitic insects and the author discussed
their method of life in all stages the manner
IN which they attack other insects, the
question as to what insects are attacked by
them, the subject Of an exceptional p.ant-fced-
ing habit, and the question Of parthenogenesis
or reproduction by virgin females. which occa-
sionally occurs among them. The paper was,
IN fact, comprehensive review Of the entire
biology OF the family.