270 



SCIENCE-GOSSIP. 



[Dec. 1, 1865. 



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 perform- 

 ance 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 ob- 

 served, 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. 



A BLACK CRADLE. 



'E 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 deeplj'-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 explana- 

 tory 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 ex- 

 hibited in the Museum of the Boyal Gardens at 

 Kew, an enormous colander-like object, of a sub- 

 stance 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, 27| inches ; out- 

 side diameter, to the ends of tubes as now remain- 



ing, 39| 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 aifording an almost im- 

 perceptible 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, undistui-bed 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 vfhole 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- 



