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of microscope, and the successful results it gives, are reasons why every one who can afford it should add it to his microscope. Its superiority over the single-tubed instrument is most strikingly shown when used in the examination of opaque objects. These stand out in bold relief, and with a solidity unattainable by the ordinary microscope. By this invention, the penetrating power of an object-glass seems to be greatly increased, and by its aid we dive, as it were, deeper into those tissues and structures that form the objects of our investigation; but when applied to the examination of transparent objects, its performance is not equal to that of the single-tube instrument, which, to my mind, gives a clearer and sharper image than the binocular. The latter, however, be it observed, can be readily reduced to the condition of an ordinary microscope by the withdrawal of its prism.

In conclusion, we may add that whatever may be the form of stand chosen by the purchaser, it should possess the qualities we have described,—a steady solid base, an equal distribution of the parts which it supports, and a smooth and even movement wherever motion is required.T. K.

We are indebted to the Editor for introducing to notice, in the April number of Science Gossip, Dr. Seemann's interesting little volume, and for a charming generalizing sketch of the nature and uses of Palms, headed by the pretty quotation from the poet Laureate, "Under a palm-tree." But poor Enoch Arden's dreams never pictured to him the extraordinary sort of cradle (or bowl-shaped socket) in which Mr. Swinburne Ward, H.B.M.'s Commissoner of the Seychelle Islands, in a letter addressed to our so deeply-regretted friend Sir W. J. Hooker, describes the Seychelle Islands Palm (Lodoicea) to be rocked and lulled, and the noble trunks thus preserved from injury when struggling against the force of violent gales. Many explanatory particulars yet seem wanting to enable us fully to understand the nature and uses of this most extraordinary appendage, so different from what is known of any other tree.

There has recently been received, and is now exhibited in the Museum of the Royal Gardens at Kew, an enormous colander-like object, of a substance as hard and close-grained as black lava, pierced with numerous holes, about the size of a thimble, and each hole communicating with a hollow tube, which tubes bristle round the outside of the bowl like roots, and no doubt have been the cases or conduits of roots, if not the hardened bark of the roots themselves.

The accompanying figure and measurements were taken from the specimen at Kew: inside depth of bowl, 23 inches; inside diameter 27½ inches; outside diameter, to the ends of tubes as now remaining, 39½ inches. Through these hollow tubes, says Mr. Ward, the roots penetrate the ground on all sides, never, however, becoming attached to the bowl, their partial elasticity affording an almost imperceptible but very necessary play to the parent stem, when struggling against the force of violent gales. Mr. Ward says, that, unlike the Cocoa-nut Palms, which bend to every gentle gale, and are never quite straight, the Coco-de-mer trees are as rigidly upright as iron pillars, undisturbed in their position by the heavy gales and violent storms so often occurring in tropical regions. Dr. Seemann (who, however, does not write as an eye-witness), on the contrary, says, speaking of these same Lodoicea Palms, the diameter of the trunk varies from 12 to 15 inches, and the height from 80 to 90 feet, and the whole stem is so flexible that the tops

of those trees which stand in each other's vicinity strike against and chafe each other in a strong breeze, making an extraordinary noise!

Which of these accounts are we to rely upon as correct?

One of the greatest and most ennobling pleasures attending on all natural history investigations, is the contemplation of that fitness and perfection of contrivance, which gives us everywhere the most striking examples of adaptation of structure to requirements. Now, if we admit as certain the premises that the stiff rigidity and want of supple-