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INARCHING TO SUPPLY VACANCIES IN FEU IT TEEES. 
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Bolbophyllums, have yet a hornless column, fom' pollen masses, and large leathery flowers. The new 
genus is intermediate between the Dendrobes and Bolbophyls. — (Paxt. Fl. Gard. i., 154). 
The root-point (spongiole of De Candolle) is a very curious portion of the plant. It is distinguished 
externally by its globular shape and lighter colour- ; internally by the circumstance that neither vessels 
nor the accompanying extended cellular tissues penetrate into it. This last character has been hitherto 
overlooked. The lower portion of 'the root-point consists of rather large, angular cells, containing globular 
grains of starch collected into a mass, and turning blue with iodine. In those root-points of the Hyacinth 
which I have examined, this has always been the case ; but in the root-points of other plants, the granules 
hi the cells have turned brown with iodine, as occurs also in the upper cells of the Hyacinth. The cells of 
the root-points are round or angular, larger or smaller, and even extended transversely ; and there are 
always to be found on the outside some cells which scale off, and in their places others are produced which 
in their turn scale off, thus constituting the well-known scales of the root-points. Many philosophers have 
believed that the root-points served to suck up the nutritive juices from the soil, and L)e Candolle on that 
account called them spongioles; but the very accurate observations of Ohlert (Linncea, 1837, p. 609) 
prove that this is not at all the ease, for plants whose root-points hang free in the ah- continue to grow 
even when these points are cut off and closed with sealing wax, only in that case it is necessary that 
the roots themselves be in water, or in moist earth above the points. It is worthy of remark that 
precisely at the point where the absorbing surface commences, there also the vessels with their 
accompanying cellular tissue commence. — {Link in Journ. Sort. &'oc, vi., 29). 
In mule 2>tants, especially when obtained from such as have long been cultivated, or between 
species which have a very intimate elective affinity, and are so closely allied to each other as to appear 
merely varieties, slight differences as of form and colour sometimes occur, but have no constancy and 
cannot be obtained with certainty on repeated experiments. Mr. Herbert supposed variations of this 
kind to result from the application of a quantity of pollen insufficient to produce a real typical mule, 
though potent enough to produce slight changes. Gasrtner is opposed to this notion, on the ground 
that experiments seem to show that the completeness or incompleteness of impregnation influences 
merely the perfection of the fruit and seeds, and that a quantity of pollen insufficient for the impreg- 
nation of an ovarium produces only imperfect fruit and seeds, but gives rise to no distinct type ; for 
unless a proper quantity of pollen be applied, the seeds are never perfected, or the embryo is inert. — 
Journ. Hort. Soc, vi., 3). 
The Barbacenia Rogicrii, figured in our vol. ii. (p. 209), was raised from seed in Mr. Van Houtte's 
establishment at Ghent. M. Van Houtte informs us, that it is of hybrid origin, having been obtained 
by fecundating Barbacenia sanguinea with B. purpurea. Its name commemorates the Belgian Minister 
of the Interior. The plant, which is a very fine stove perennial, is sufficiently distinct as an object of 
culture, from B. purpurea, with which some persons have thought it synonymous. — M. 
INARCHING TO SUPPLY VACANCIES IN FRUIT TREES.* 
M T Corbeil, near Paris, some Pear Trees have been managed in a peculiar way by M. Fourke. They 
lAA are fine trees, covering a wall, and trained horizontally ; but they were not planted when young, 
and trained progressively in order to produce this regularity. On the contrary, they were planted 
when large and irregularly grown, having in some places a redundancy, in others a deficiency, of 
branches. Various means are frequently resorted to with the view of supplying branches where 
wanting ; such as notching, budding, or side-grafting the stem ; but here the desiderata were 
obtained by inarching the growing extremities of adjoining shoots to the parts of the stem whence the 
horizontals should proceed. Supposing the branches of a tree are trained horizontally a foot apart, 
with the exception of some where the buds intended to produce branches did not break, as is often 
the case ; then a shoot is trained up, and, when growing hi summer, a small slice is taken off near its 
extremity, and a corresponding extent of surface immediately below the inner bark of the stem is 
exposed ; the two are joined together, and the point of the shoot is inclined in the proper direction to 
form the branch. The most remarkable feature in the trees at Corbeil is the uniformity of vigour 
in the respective branches. This is a great advantage which the mode possesses over budding or 
side-grafting. At the distance of a foot apart for the horizontal branches, it takes as many years to 
cover the wall as the latter is feet in height. The intermediate stage might, however, be readily 
supplied by the method above detailed ; and a wall twelve feet high might be covered as well in six 
years as it otherwise would be in twelve. — JR. Thompson: 
9 Journal of the Horticultural Society. 
§P^ 
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