A description is given of the intracellular bodies in the leaves of
Lilium speciosum f.
rubrum affected by mosaic disease. They are usually conspicuous, can be observed in living cells, and are vacuolate and perhaps of plasmic nature; vary considerably in shape and size. They are usually round to ellipsoid, but not commonly very irregular in shape. They range from 6.9 to 34.3μ in width and 8.9 to 68.6μ in length, in many cases larger than the host nuclei themselves.
On the seriously affected plant, they are abundantly seen in all epidermal cells of leaves, but in early stage of development of the disease, they are either entirely absent or scanty. In the latter case they are mostly in close contact with the host nuclei, round in shape, without vacuoles, and look like the aggregates of particles.
The intracellular bodies are easily stained by several dyes, acidic or basic, of which Heidenhein's iron-alum haematoxylin give most excellent result. When they are treated with 0.5 per cent safranin and then differentiated by N/5 hydrochloric acid, they are stained coral pink and the host nuclei tyrian rose, so that both structures are easily distinguishable from each other. As to the affinity against the dyes the bodies are generally weaker than the nuclei.
Treated by osmic acid, the bodies turn yellow but not black after 18 hours in its 1 per cent solution. The MILLON'S reaction is always negative.
The bodies remain intact in 15 per cent sulphuric acid for 5 minutes, and are not soluble in alcohol, ether or chloroform. But in N/5 caustic soda solution, they disolve rapidly.
The determinations of the hydrogen-ion concentration of these bodies and the host nuclei were made by colorimetric method, as described in detail by SMALL. The result of this experiment has indicated that both are evidently acidic, and their pH lies between almost 4.0 and 4.8.
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