4o 



HARD IV J CKE ' S S CIENCE- G SSIP. 



duction. That the uppermost leaves on a stem should 

 be starved, aborted, or degraded is not indeed what 

 one would expect, considering that leaves are organs 

 of nutrition each of which makes the plant that bears 

 it richer as it grows. Look at a young plant of the 

 scarlet-runner, the second pair of leaves is larger than 

 the first. So it is with peas and other plants raised 

 from seed, that the leaves are larger as they are in- 

 creased in number, the later leaves having an ad- 

 vantage in the nutriment elaborated by those that 

 came before. We might therefore expect that a 

 plant having no definite limit to its power of growth, 

 an exogenous tree, would go on lengthening upwards 

 till it should reach the height at which its leaves 

 would be starved by reason of the rarefaction of the 

 atmosphere. Such however is not found to be the 

 case. The length of a branch bearing leaves is 

 evidently determined by some other principle than 

 the nourishment which the leaves afford and which is 

 not all spent in provision for the leaves which come 

 immediately after, but stored up in bulb, come, tuber 

 or rhizome, or it may be in a woody stem. Thus it is 

 that the upper leaves upon a stem may be starved, 

 aborted, or degraded at the same time that the plant 

 is laying up a store of nourishment. This procedure 

 of a plant may be compared to the conduct of a man 

 whose bodily strength is exhausted by work till he 

 is no longer able to stand up long enough to earn 

 fourpence by manual labour, but who has laid up so 

 much of what he had already earned as to have 

 capital at his disposal which he may use to gain a 

 profit. By such an expenditure of capital, a plant 

 produces flowers, fruit, and seed, as we may some- 

 times notice in an old apple-tree covered with blossom 

 and afterwards with fruit though so weak from age 

 that it can hardly form a leafy twig as long as your 

 little finger. — JoJui Gibbs. 



Dielytra spectabilis. — As the naturalisation of 

 foreign species ought always to be placed on record, 

 it may be mentioned that near Coates, Sussex, this 

 pretty flower, doubtless a garden outcast, has become 

 well established during the last few years in woods in 

 the neighbourhood, and will doubtless attract the 

 attention of future observers. It may also be noted 

 that, both as to foliage and flowers, it has so deterio- 

 rated that it has a very different aspect from the 

 cultivated plant. Like other of the Fumariacere, 

 such as Corydalis hitca, it may possibly become a 

 recognised alien in our flora. — F. II. Arnold. 



Raphides. — At a recent meeting of the Jena 

 Naturalists' Society, Frof. Saahl read a paper on the 

 meaning of those excreta of plants called Raphides, i.e. 

 crystalline needles often found in the cells in large 

 quantity. From experiment he inferred that they 

 were a protection to plants against being eaten by 

 animals. Many animals avoid plants with raphides, 

 or eat them reluctantly ; and some animal, e.g. snail 



species, in eating plants that have raphides select 

 those parts that are without the crystals. Many 

 plants held for poisonous, e.g. Arum maculatum, owe 

 their burning taste simply to the very numerous 

 raphides, which, forced out of their cells, enter the 

 tongue and palate. The juice obtained by filtration 

 has quite a mild taste. 



GEOLOGY, &c. 



The Discovery of a Gigantic Turtle by Dr. 

 Donnezan. — This specimen was found, with numer- 

 ous other fossils, in the middle Pliocene of Perpignan 

 during the recent excavations connected with the 

 erection of the fortress of Serrat in the Eastern 

 Pyrenees. The carapace, 1*20 metre long, was ex- 

 tracted with great difficulty from the hard rock in 

 which it was completely imbedded, the innumerable 

 fragments being carefully put together by Dr. 

 Donnezan, by means of about a thousand brackets. 

 This turtle, which he has presented to the Paris 

 Museum, considerably exceeds its living congeners, 

 being equal in size to the T. gra?ididier, a sub-fossil 

 species found in Madagascar. Its survival down to 

 the close of the Middle Pliocene is important for the 

 study of the glacial period, tending to show that the 

 South of France even then still enjoyed a warm 

 climate. 



The Correlation of some of the Eocene 

 Strata in the Tertiary Basins of England, 

 Belgium, and the North of France. — Prof. 

 Joseph Trestwich has recently read a paper on this 

 subject before the Geological Society. Although 

 the relations of the several series have been for the 

 most part established, there are still differences of 

 opinion as to the exact relation of the Sable de 

 Bracheux and of the Soissonnais to the English series ; 

 of the Oldhaven Beds to the Woolwich series ; and 

 of the London Clay and Lower and Upper Bagshots to 

 equivalent strata in the Paris basin. The author 

 referred to the usual classification of the Eocene Series, 

 and proceeded to deal with each group in ascending 

 order. The Calcaire de Mons is not represented in 

 England, but may be in France by the Strontianiferous 

 marls of Meudon. It contains a rich molluscan fauna, 

 including 300 species of Gasteropods, many of which 

 are peculiar, but all the genera are Tertiary forms. 

 The Heersian are beds of local occurrence, and Prof. 

 Prestwich sees no good reason for separating them 

 from the Lower Landenian or Thanet Sands. He 

 gave reasons for excluding the Sands of Bracheux 

 from this group. Out of twenty-eight Pegwell-bay 

 species, ten are common to the Lower Landenian, and 

 five to the Bracheux Sands, which present a marked 

 analogy with the Woolwich Series. These Sands of 

 Bracheux are replaced in the neighbourhood of Paris 



