372 Oil Bodies in the Cherry Laurel Leaf. 
chlorophyll by the drops. The short immersion in alcohol would 
serve to extract some of the chlorophyll from the chloroplasts, and 
the green colouring matter was taken up by the drops till they 
appeared bright green. Experiments were then made to test 
whether such an action would take place under these conditions. 
An emulsion of oil and water was made and placed on a slide— 
that is small spherical bubbles of oil were present in a general 
medium of water. To this an alcoholic extract of chlorophyll was 
added, by running under the cover-slip. It was found that the oil 
drops took up most of the green colour, leaving the surrounding 
medium only slightly tinted. 
The partition in a test-tube was also tried. As an example, 
cedar-wood oil was shaken up with some alcoholic chlorophyll 
extract and the whole allowed to stand and settle out. Most of the 
green colour went into the oil, leaving a pale green layer of alcohol 
floating upon the oil. 
It was thought that sections known to contain oil might react 
in the manner. Sections of castor-oil seeds (RicinusJ were cut, 
left in water for some time to allow the oil drops to run together 1 
and then stained with an alcoholic solution of chlorophyll. It was 
found in this case also that the spherical oil drops stained green and 
had then much the same appearance as the bodies in the leaf. It 
seems certain then that the green colour of the oil drops in the leaf, 
is due to the taking up of chlorophyll from an alcoholic solution. 
As the chlorophyll fades from a section of the leaf treated with 
alcohol as described, the oil bodies become more conspicuous by 
contrast, as they keep their green colour for a longer time than the 
chloroplasts. In still older preparations the green colour disappears 
altogether from the chloroplasts and the oil drops become dark 
brown in colour, when they are even more conspicuous. 
The oil drops or oil bodies are usually spherical in form, are 
slightly larger than the chloroplasts and fairly uniform in size. As 
a rule there is one only in each palisade cell, occupying a more or 
less central position. Sometimes there are two present. A few 
occur also in cells of the lower mesophyll and sometimes even in the 
lower epidermis. 
In nature they are probably similar to the oil bodies described by 
Radlkofer, Monteverde and others and mentioned in Zimmermann’s 
Microtechnique. 2 Monteverde 3 describes oil bodies, uniform in size, 
which occur singly in the mesophyll cells of the crystal-free Grasses. 
They also occur in the palisade and spongy mesophyll of the leaves 
of numerous other orders of plants. Monteverde considers that 
they are comparable with the oil bodies which occur in Liverworts. 
Whether the bodies in the Cherry Laurel leaf are exactly 
similar to those mentioned is difficult to say, but their presence 
should certainly be noted in such a well known type-leaf as this. 
1 Strasburger & Hillhouse, Pract. Bot., 6th Ed., 1908, p. 33. 
2 Zimmermann, Bot. Microtechnique, Eng. Trans., 1893, p. 210. 
* Monteverde, Bot. Centralbl. 43, 1S90, p. 329. 
Botany School, S. REGINALD PRICE. 
Cambridge. 
April, 1912. 
