(3

Aggregation

1881

Aug 11— Euphorbia peplus — Plants watered night before dug up & put into water — many fine roots with root-caps perfect. — Placed in Sol. of C. of amm 2 or 4 to 1000, (with some water under cover glass) much aggregation take place — many cells which examined before were seen to be quite transparent became more less filled with yellowish brown minute spheres.— Close to growing point no such change, though I suspect the still colourless protoplasm contracted — A little above growing point the cells became filled so completely with these masses that they look dark brown & are opake. — These cells are squarish masses of brown matter are larger where from analogy lies the chief zone of growth. Higher up roots they are rather abruptly succeeded by the cells with scattered spheres & such cells extend far up roots. The cells with granular matter run in rows & often alternate with transparent

4

Euphorbia

Aggregation

or empty cells— Such cells sometimes are found singly— & a row of filled cells sometimes interrupted a few empty cells. — In growing zone cells filled with brown matter could be sometimes seen which from size & shape had obviously just divided.

The roots present an extraordinary appearance in this condition. — In one case tip of root was left outside covering glass, & after c. of Am: was given to the tip, aggregation was seen commencing at about .07 of an inch from tip after interval of 2' 30". —

Several rows of cells with such matter round the root.

After exposure to C. of amm (2 to 1000) for about 50 hr' the aggregated dark opake balls near tip instead of being almost square are now rounded & there is much more granular matter in the alternate rows of cells above the tip. This great (over

[4v]

difference (seen after alcohol & after Phosphate of ammonia) in the generally alternate rows of cells near tips of all the roots is a very remarkable phenomenon, & indicate some important functional differences in the cells of the roots. —