232 
POPULAR FIELD BOTANY. 
open situation on the slope of the mountain, 
where the soil, and likewise the position of 
the roots, ensured it from too great moisture. 
Its flowering time was in June, on till Sep- 
tember, and the fruit ripened in February. 
It begins to bud at the commencement of the 
rainy season ; while the heat of the sun and 
the dry atmosphere are favourable to the de- 
velopment of the fruit and the ripening of 
the seed. 
The difference in the average heat during 
the dry winters and the wet summers amounts 
only to 1° 5' Reaum. The greatest difference 
perceived in the day temperature during a fort- 
night was only an increase of half a degree ; 
while, in the month of January, Dr. Karsten 
observed the temperature to be 13° 12' Reaum. 
(63° Fahr.), and, in September, 15° 12' Reaum. 
(67° Fahr.) The plant may, therefore, be 
grown artificially with a like temperature. 
It ought to be observed, however, that it may 
be as successfully treated if the condition of 
the soil in connexion with the atmosphere is 
attended to. " The temperature of the at- 
mosphere," writes Dr. Karsten, " admits of a 
certain variation, if only the average minimum 
of the night-heat is in keeping with the 
maximum heat during the day, supposing the 
situation to be somewhat shaded. In the 
month of March I observed the first to be 
8° 1' Reaum. (50° Fahr.), and the latter, in July, 
was 22° 75' Reaum. (83° Fahr.) This differ- 
ence, however, is virtually considerably in- 
creased by the direct rays of the sun, while 
the heat of the ground in the tropics is gene- 
rally greater than the average heat of the at- 
mosphere. It is of the greatest importance 
to kmow the proper treatment of plants that 
have their roots deep in the ground. The 
decrease in the temperature of the atmosphere 
regularly ensues at the period when the heat 
of the day is greatest ; and the temperature 
of leaves, as well as of the soil, is not lessened 
though immersed in water. The greatest 
care is necessary in the treatment of the roots ; 
indeed they ought to receive as much atten- 
tion as those parts which are above ground. 
The points of the roots, or spongioles, are 
those parts which claim the chief considera- 
tion, as they are eminently essential to the 
health and general well-being of the plant. 
They consist of a substance with the softest 
texture, and ai'e almost unprotected from 
external influences ; they gather from the 
heat and moisture around them the nourish- 
ment necessary for the life of the plant ; and 
the slightest interruption to the healthy play 
of this important organ is prejudicial to the 
plant. In a natural condition, one plant 
gi'ows with a long tap-root, while the next to 
it may have fibrous, tufted, or matted roots, 
which spread far out and keep near the sur- 
fjace. But, grown in pots, they must adapt 
themselves to the surrounding circumstances, 
and must be supplied with those materials 
most suitable for them. Those which are of 
a firm and upright form, spread their roots in 
the soil in a similar manner ; projecting and 
spi'eading in all directions, even beyond the 
limits of the pot in which they are placed, in 
quest of moisture and the nourishing gases 
which are essential to them." 
The plant under notice has been named 
by Dr. Karsten in honour of Dr. Stannius, 
a German professor of anatomy and phy- 
siology. 
POPULAR FIELD BOTANY."" 
We have here a volume that may be profit- 
ably consulted by every child, and the sub- 
jects they are called upon to contemplate may 
be found in the highways and hedges. To 
those who do not travel hoodwinked, but exa- 
mine the natural beauties that spring up in 
their paths, this book will form a pleasing 
companion. It contains between seventy and 
eighty coloured plates, which represent many 
of the leading British plants ; and it would be 
an excellent task for youth to find, by means 
of these plates and the descriptions attached 
to them, specimens to form a complete liortus 
siccus. The following passage from the Intro- 
ductory Chapter is quite true, and may be 
impressed upon the young mind with advan- 
tage :— 
"If a science is worth learning, it is wise 
to begin properly, and study the alphabet as 
it may be called ; and although I have said 
there is no ' royal road' to Botany, I have 
endeavoui'ed to render all as easy and simple 
as possible in this little treatise on the sub- 
ject, by using English words instead of the 
technical terms wherever it is practicable. 
" No one must expect, if they pursue Bo- 
tany merely as a relaxation from more import- 
ant studies, to be acquainted with it in a 
season. Botanists have been pursuing it for 
years, and if asked, would say they knew 
but little compared to Avhat they wished to 
know : it would therefore be presumptuous in 
the young to expect that after a few trials 
only they are to understand the subject tho- 
roughl}'- ; for as it is impossible to arrive at a 
knowledge of any science or art without great 
pains and considerable industry, (and Botany 
is not an exception,) the learner must be re- 
solved to meet and overcome obstructions, 
which at the commencement appear rather 
alarming ; but with a little attention the^ first 
* " Popular Field Botany." By Agnes Catlow, 
Author of " Popular Conchology." London : Eeere, 
Benham h Reeve. 
