[ —  —— = * a all . if 
608° Monthly Botanical Report. . [July ‘ 
- gins to ascend throuzh the alburnum. The plumule in consequence elongates, its leaves ene 
large and unfold; and a set of vessels, which did not exist in the root, are now brought inta 
action: ‘There, which [ have called the central vessels, surround the medulla, and, between 
-it and the bark form a circle vpon which the alburnum is deposited by the bark, in the form 
of wedyeés, or like’the stones of an arch. Through these vessels, which diverge into the leaf~ 
stalks, the sap ascends, and is dispersed through the vessels and parenchymatous substance of 
. the leaf.~ And in this organ, the fluid, recently absorbed from the soil, becomes conyerted 
-Gnto the-true sap or blood of the plant. And, as this fluid, during germination, descended 
“from the cotyledons and seed-leaves of the plant, so it now descends from its proper leaves, 
‘and adds, in its descent, tothe bulk of the stem and the growth of the root. Alburnum is 
tilso deposited in the stem of the plant below the proper leaves, as it was previously deposited 
below the sved-Jeaves. And from this spring other central yessels, which give existence toy 
@nd-feed, other leaves and buds. ' , é ‘ 
A’péttion of the true sap appears, in its descent down the bark, to secrete into the albur- 
num, through passages correspondent to the anastomosing vessels of the animal economy. 
¥lence the® ascending fluid "becomes ‘mixed with a portion of the descending sap in the 
elburnum. , 
The full-grown leaves prepare the fluid which generates other young leaves, the health 
and growth of whith ere 2s much dependant upon the full-grown leaves, as those, when first 
formed, were upon the cotyledons, 
. The power of each proper leaf to generate sap, in any given species and variety of plants 
4ppéafé to be ‘in a compound ratio of its width, its thickness, and the exposure of its upper 
éurface to the light in a proper temperature. The mature leaves increse rapidly in propor- 
tion to the young leaves, and the creation of sap consequently exceeds the expenditure. It 
4s therefore accumulated during a succession of weeks, or months, or years, according to the 
poatural habits ahd duration ‘of the pldnt; and varying considerably according to the soil 
and climate. ‘The sap; thus’ generated, is deposited in the bulb of the tulip, in the tuber 
of the potatoe, in the fibrous roots of grasses, and in the alburnum of trees, during winter 5 
f€nd is dispersed through their foliage and bark during the spring and summer. _ . 
When the plant has attained puberty, a portion of its sap is expended on its blossoms an 
fruit; which are fed by vessels apparently similar to those of the succulent, annual shoot and 
leaf stalk, and which probably convey a similar fluid; fora bunch of grapes grew.and ripened, 
» when grafted on a leaf-stalk. ¥ “ 
The fruit or seed-vessel appears to Lc generated always by the prepared sap of the plant, 
and its chief office’to be to adapt the fluids to the proper nourishment of the seed. , 
Mr. Knight has illustrated the above theory by an application of it to the culture of the 
Melon; @ fruit which is so often found to be so defective in richness and flavour, as to be 
hardly worth cultivating. ‘This detect Mr. Knight found by experiment to be owing to the 
want of a sufficient number of leaves, exposing their upper surfaces to the light. For the 
sténis and footstalks of the melon under the hot-bed frame are so weak, that when the leaves 
are displaced from their proper position, they are not able to regain it. This observation led 
him to direct that more care should be taken to preserve the leaves in theix natural position, 
with the upper surfaces exposed to the light, which was effected by the aid of little wooden 
hoeks, with which the trailing stems, and even the footstalks of the leaves were secured in 
their propet places; and by avoiding pouring the water in the usual way upon the leaves of 
the plant; using instead of a common watering-pot, one with a spout adapted for pouring 
the water upon the tiles which cover the bed, without touching the leaves. By this manage- 
+ ment Myr. Knight found that his melons were no longer defective in richness and flavour. , 
* It may be of use to mention here, that the variety of melon which Mr. Knight exclusively 
evltivates, on account of its superior flavour, and which we believe is little known to culti- 
vators in general, is the gne that was imported by Mr. J. Hawkins from Salonica. The form 
of this variety is nearly spherical, without any depressions upon its surface. Icis of a golden 
eolour, and its flesh periectly white. “This kind Mr. Knight says continues to improve in 
flavour and fichness till it becomes externally soft, and betrays some symptoms of decay 
‘The consistence of its flesh.isethen hearif that of a water-melon; and its taste sa sweet, that 
few will think it improved by the addition of sugar, The weight gf a good melon of this 
yariety is about seven pounde. pi : = ee oe eee 
The tenth volume of the Transactions of the Linnzwan Scciety is published. 
Dr. Smith has given us a translation of Linnzeus’s Your in Lapland, now first published from 
the'manuscript journal. Tt isin two volumes octavo, and is illustrated by wooden cuts, being 
fac-similes of the pen and ink sketches in the original. ‘ % ae ie 
A journal of a (botanical) Tour in Iceland, by Mr. William Jackson Hooker, is printed, 
but not published. het ar: : diet fh ae aa 
~The first volume of the Transactions of the Wernerian Society, Edinburgh, is only inte- 
resting to the botanist, om account of a paper on the natural order of Coniorte of Linnzeus, by 
Mr. Brown, of which we hope at a future time to give some accoynt to our readers. . t 
Men ae ov ose oMONTHLY 
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oA ots 
