65 
Beer. — On Elaiop lasts. 
corresponding to those discovered by Wakker in Vanilla , have up to the 
present been found only in Monocotyledons, with the single exception of 
Psilotum reported by Zimmermann. 
Moreover, apart from a few quite insufficient observations we are still 
entirely in the dark regarding their true nature, their significance, their 
origin, and their fate. 
During some observations upon the pollen-grains of Compositae I was 
interested to find bodies which resembled the Monocotyledonous elaioplasts 
occurring in the tissues of the floral region of Gaillardia Lorenziana k 
This would extend the distribution of elaioplasts to a member of the 
Dicotyledons. 
My first endeavour was to make sure that I was dealing with true 
elaioplasts. In the hairs upon the corolla of young flowers, where I first 
observed these bodies, they occur as more or less spherical, highly refractive, 
granular structures usually somewhat larger than the nucleus, and in most 
cases lying singly in a cell, although two or even more such bodies were 
occasionally met with. 
Their reactions were found to be as follows : — 
1. Heated gently upon the slide (whilst lying in a physiological salt 
solution), drops of oil are exuded from their surface (Fig. 13). 
2. Osmic acid (as this occurs in Flemming’s stronger solution) turns 
them black or brown. 
3. Potassium bichromate after twenty-four hours’ action leaves them 
quite colourless, but causes the extrusion of oil globules as in 1. 
4. Alkannin solution in 60 per cent, alcohol colours the bodies 
deeply red. 
5. Iodine (in KI) colours them brown and causes the extrusion of oil- 
globules (Fig. 12). 
6. Absolute alcohol dissolves out the oil from their interior and leaves 
them vacuolated. 
7. In strong HN 0 3 (warmed), followed by NH 3 , they give the 
Xanthoproteic reaction (viz., deep yellow coloration). 
8. Glacial acetic acid after twenty-four hours’ action causes great 
extrusion of oil drops but no solution. 
9. 10 per cent. KOH. after twenty-four hours’ action dissolves neither 
stroma nor oil drops. 
These reactions, combined with their general appearance, show that the 
bodies occurring in the hairs of Gaillardia are in all respects similar to the 
elaioplasts described by previous authors. 
In very young hairs from capitula which were still quite small and 
1 Gaillardia Lorenziana is a German variety of G. picta , which itself appears to be only a garden 
variety of G. pulchella. I have not yet had an opportunity of examining any other form or species 
of Gaillardia except the one mentioned above. 
F 
