1913] CURRENT LITERATURE 165 
hydroid phase, hence the chloroplast is generally homogeneous when viewed 
with either the microscope or the ultramicroscope. The hydroid phase of the 
chloroplast absorbs considerable additional water when it is brought into 
direct contact with this agent. This disturbs the dispersion of the two phases 
and the green pigment accumulates in various regions, giving the plastid a 
granular appearance. This, the writer believes, is not a complete separation 
of the two phases, for the green granules are not as dark colored as the separate 
drops of the pigment, and the lipoid phase will not strain with Sudan III nor the 
hydroid phase with neutral red, both of which occurs in a true separation of 
the two phases. Water solutions of various alcohols in concentrations too low 
to coagulate the hydroid phase hasten and accentuate the deformation caused 
by distilled water, but do not cause a true separation of the two phases. If 
the alcohol is sufficiently concentrated to coagulate the hydroid, a complete 
separation occurs. In this process the separation of the pigment passes from 
amicronic dispersal through submicronic (particles visible to the ultramicro- 
scope but not to the microscope) and micronic (visible to the microscope) to 
complete separation. This work gives quite a different picture of the relation 
existing between stroma and pigments in the normal chloroplast from that 
generally depicted in texts. The texts generally speak of the pigment being 
held in the meshes of the spongy stroma or aggregatéd in the outer layers of 
the plastid. The author can gain either of these pictures by one or another 
method of deformation. He does not deny that such a deformation occasion- 
ally occurs even in the living active cell, but the chloroplast is generally homo- 
geneous and shows amicronic distribution of the two-phase system. 
agrees with the dispersal of the various phases in the protoplasm which is 
optically empty aside from the microns in it. Plastids of the various plant 
groups vary in their consistency and resistance to agents; those of the Florideae 
are most nearly liquid. 
By use of alcohols as solvents, the author was able to obtain crystals of 
the green pigments from many green plants, ranging from the algae up. e 
form and structure of the crystals vary with the alcohol used. The advance 
of our knowledge of the chemistry of chlorophyll during the last half-decade 
enables us to state with reasonable certainty the general constitution of the 
green pigments as they exist in the plastid, also of the crystalline products 
in methyl and ethyl alcohol. Tswert’s contention that there are two green 
pigments (termed by him a and 8 chlorophyllin) has been confirmed by WILL- 
STATTER, who has shown that they are different oxidation stages of the same 
substance. According to this writer one of them can be represented as follows: 
f (OOH 
Cult Mg—COOCH, 
\co0CaHy 
The molecule bears three carboxyl groups. One is free, another bears a methyl 
group, and the third a phytol group. In extraction with ethyl alcohol the 
