20 



HARDWICKE'S SCIENCE-GOSSIP. 



[Jan. 1, 1869. 



BOTANY. 



Oxalis acetosella. — The Wood Sorrel pro- 

 duces seed throughout the summer and autuirm 

 from a petalous flower, exactly after the fashion of 

 the Sweet Violet ; but I cannot find the fact noticed 

 in any book. At the present time there may be 

 found any quantity of seed-vessels in all stages of 

 ripeness, yet no flowers have been seen since the 

 early summer. — Robert Holland. 



Bud-variation. — I have now in my garden a 

 very beautiful example of what Darwin calls bud- 

 variation. A plant of Snapdragon, which grows with 

 two main branches, produces on one of them crimson 

 flowers with the orange tinge and orange blotch on 

 the lower lip, so frequently seen ; the other branch 

 produces flowers of a pure crimson colour, having a 

 white tube. At first I thought that two plants 

 must have been planted close together ; but I have 

 traced the branches down below the soil, and I find 

 they proceed from one root. In all probability the 

 variety has resulted from a cross between two seed- 

 ling varieties, which had flowers of the respective 

 colours ; but from the fact of the plant being so 

 distinctly forked from the base, I should think that 

 the branches are not exactly sporting by simple 

 reversion to the colours of the two parents, but 

 that the seed had contained two embryos, a circum- 

 stance of not unfrequent occurrence in acorns, nuts, 

 and chestnuts, and which we see oftener than not 

 in mistletoe. — Robert Holland. 



Ranunculus tripartitus, D.C. — ("R. V.T.")— 

 The specimen sent from Withiel, Bodmin, belongs 

 to this species. Mr. Keys, in his " Elora of Devon 

 and Cornwall," localizes it "near the Land's End," 

 but names no other locality for it. In the " Com- 

 pendium of the Cybele Britannica," the counties 

 of Cornwall, Dorset, Hants, Kent, Surrey, and 

 Pembroke are named for it. "R. V. T." re- 

 marks that at Withiel it was " found growing with 

 R. hederaceus : in general appearance it differs from 

 R. hederaceus wherever growing, but it very much 

 resembles it in habit and situation."— i?. 



Laurel-leaves. — I hoped to have seen in the 

 last two numbers of Science-Gossip some further 

 information respecting the peculiar markings at the 

 back of the leaves of the Common Laurel, noticed 

 by "H. TV. W." in the August number, p. 191. 

 There is no doubt that these marks exist; I have 

 found them on every leaf that I have looked at, and 

 I have examined a great many since I read your 

 correspondent's remarks. They do not appear to me 

 to be wounds caused by insects; for in the early stage 

 they seem like mere depressions in the leaf, after 

 which a round piece of thickened epidermis appears. 

 I cannot detect the slightest wound, nor any minute 

 larva under the skin. In this stage they look very 

 like some natural peculiarity of structure in the 



leaf ; but after a while they become pale brown in 

 colour, and there is a mass of brown cells under the 

 skin, causing a slight elevation of the surface. In 

 this stage they have all the appearance of fungous 

 growth. In old leaves there only remains a brown 

 scar of hardened membrane. The marks always 

 seem to occupy the same position on the leaf as 

 described by " H. TV. TV." I have not been able 

 to detect anything like them on any other leaves, 

 except on those of the lilac, where I have found a 

 few spots somewhat similar in their early stage, but 

 which are evidently caused by the attacks of a 

 fungus, the black spores of which can, at a later 

 stage, be plainly seen bursting through the epi- 

 dermis. But the spots on lilac-leaves are not by 

 any means universal as on the laurel. It is to be 

 hoped that the subject may be further investigated; 

 for at present these marks, their nature, cause, and 

 use, seem to be amongst the obscure points of 

 vegetable physiology. — Robert Holland. 



The Monsteria deliciosa. — In the grand col- 

 lection of plants at Dangstein, for which this place 

 is celebrated, may generally be seen in fruit one 

 of those strange species of Arads called Monsteria 

 deliciosa (or Philodendron pertusum, as it is now 

 named), the great leaves of which are exceedingly 

 ornamental, being slashed full of holes, and their 

 edges fringed by the broad ligament-like pieces 

 formed out of the uniform deep cuts towards 

 the centre or mid-rib. The singularity of the 

 fruit, too, is enough to make it equally attractive. 

 It is oblong, about 12 or 14- inches long, rather 

 curved, a deep sage green, marked all over the 

 surface by hexagonal meshes. These meshes, which 

 are fleshy and easily separated from a soft, vinous, 

 very fragrant pulp which lies beneath them, are the 

 heads of so many ovaries; and so pricking are these 

 to the tongue if it comes in contact with them that 

 the person feels uncomfortable for hours afterwards. 

 For a little foolish amusement, I have before now 

 tempted persons unacquainted with the fruit to 

 taste the underside of the covering, when they 

 have declared that they should never forget it — not 

 pain exactly, but uneasiness. When these heads 

 are removed, the lower part of the ovaries, which 

 is the part eaten, can be easily detached from the 

 somewhat woody axis over which they stand in the 

 closest possible order. I believe the plant is a 

 native of the West Indies, and the fruit may be 

 classed among the most delicious. At Dangstein it 

 is cultivated in a house along with the graceful 

 Banana, and some other tropical fruits. — George 

 Neivlyn. 



Trees by the Thames. — The Metropolitan 

 Board of Works has determined on planting the 

 Thames Embankment with trees, and the work has 

 already commenced.— Gardener's Chronicle. 



