175 
ing, as is the habit of this plant. Cereus serpentinus (Lagasca), or 
Serpent-like Cereus, had been kept out of doors since August roth. 
Previous to that time it stood under glass, where its buds were set. 
On the night of the 24th three buds opened simultaneously ; 
another bloomed in the evening of the second day afterwards, and 
another still shed radiance between the hours of 8 and 12 p.M., of 
August 22d. 
The temperature of Sunday, Sept. 2d, was decidedly autumn- 
like, being the first cool weather of the season. At 6 P.M. of that 
day the bud looked as if it might expand on the following evening. 
It had not yet the plump appearance of a mature bud. During the 
night it blew up cold, the thermometer at midnight indicated 63° ; 
at 7 A.M. of the following day it stood at 60°, and it is fair to sup- 
pose that at 3 o’clock A. M., the time of expansion of this wonderful 
bud, the mercury indicated about 55 degrees Farenheit. While the 
temperature of August 29th, at 3 p.m., indicated 90°, that of Sep- 
tember 2d, at the same hour, was only 75°. To this sudden 
decrease of temperature may be due the fact that the natural 
development of the bud was much delayed, in fact arrested, by a 
cold wave, so that the flower, which, all conditions being equal, 
should have opened on the evening of the 2d, did not expand until 
about 3 o’clock the following morning. 
From 6.30 to 8.30 A.M., the flower, which was nearly all white, 
seemed to be at its zenith of beauty. Ihad the plant photographed 
at 9 o’clock. It commenced to contract about ro A.m., and by 12 
o'clock it was almost closed. The time of inflorescence of this 
species certainly does not last more than 8 or 9 hours. Having 
repeatedly taken notes of its period of flowering, I know it to be so. 
Anthesis or the opening of the bud is perfected in about an hour’s 
time. 
There is a well defined periodicity in the flowering of all plants. 
In this case it was exceptional, the thermometrical variation pro- 
ducing a decided change in the development of the flower-bud. 
606 3d AVE., Sept. 7th. R. FE. Kunzé, M.D. 
§ 187. Florida Ferns.—During the first two weeks in May, accom- 
panied by two or three friends, I went on a botanizing expedition 
inacart. This two-wheeled Florida cart proved to be a very conve- 
nient vehicle in going into difficult roads and hard places. Our 
destination was the Halifax River, the “Settlements,’’ Daytona and 
Port Orange, about 60 or 70 miles south of St. Augustine. I found 
Polypodium Plumula, Willd., growing equally well on decaying, pros- 
trate logs, and in the ground on the bank of a constant brook at 
Daytona, and once on the trunk of a living tree, a foot or two above 
the base. This last was a fine, large specimen, well fruited. The 
fern was most plentiful by the side of the brook. I had never before 
had fruited specimens of it, except one frond that seeded in my 
fernery. I had collected the fern about fourteen miles west of St. 
Augustine, in deep woods, where it grew upon two or three inclined 
Live-Oak trees, climbing the trunks as ?. iacanum does, and, like it, 
curled up tight in dry weather. The specimens that I saw there 
were not more than eight or ten inches high, and the pinnae very 
