oung branches
brightened with an uniform phosphoric light the whole of their length;
it was the same with the surface of some of the older branches, the
greater number of which were still brilliant in some parts, and only
on their surface. I split and lacerated many of these twigs, but their
internal substance remained dull. The next evening, on the contrary,
this substance, having been exposed to contact with the air, exhibited
at its surface the same brightness as the bark of the branches. I made
this observation upon the old stalks as well as upon the young ones.
Prolonged friction of the luminous surfaces reduced the brightness
and dried them to a certain degree, but did not leave on the fingers
any phosphorescent matter. These parts continued with the same
luminous intensity after holding them in the mouth so as to moisten
them with saliva; plunged into water, held to the flame of a candle so
that the heat they acquired was very appreciable to the touch, they
still emitted in the dark a feeble light; it was the same after being
held in water heated to 30 deg. C.; but putting them in water bearing a
temperature of 55 deg. C. extinguished them entirely. They are equally
extinguished if held in the mouth until they catch the temperature;
perhaps, still, it might be attributed less to the heat which is
communicated to them than to the deficiency of sufficient oxygen,
because I have seen some stalks, having become dull in the mouth,
recover after a few instants a little of their phosphorescence. A
young stalk which had been split lengthwise, and the internal
substance of which was very phosphorescent, could imbibe olive oil
many times and yet continue for a long time to give a feeble light. By
preserving these _Rhizomorphae_ in an adequate state of humidity, I
have been able for many evenings to renew the examination of their
phosphorescence; the commencement of dessication, long before they
really perish, deprives them of the faculty of giving light. Those
which had been dried for more than a month, when plunged into water,
commenced to vegetate anew and send forth numerous branches in a few
days; but I could only discover phosphorescence at the surface of
these new formations, or very rarely in their immediate neighbourhood,
the mother stalks appearing to have lost by dessication their luminous
properties, and did not recover them on being recalled to life. These
observations prove that what Schmitz has written was not