HA RD WICKE'S S CIENCE- G OS SIR 



39 



ON THE DISCRIMINATION OF DIFFERENT SPECIES OF WOOD BY MICROSCOPICAL 



EXAMINATION. ' 



THE following is the classification of cross-sections of wood by Mr. C. J. Miiller, alluded to in the note 

 on this subject in the last number of Science-Gossip : — 



Pith Mass Circular, or nearly so. 

 A. — Edge of Woody Tissue next Pith Crenate, 



Name and Character of Medullary 

 Rays. 



sEsculus hippocastanum. — -Thin, 



crowded. 

 Berberis vulgaris, 2 years old. — 



Wide apart, thick, flexuose. 

 Sambucus nigra, 3 years old. — 



Of unequal thickness, several 



thin between two thicker 



ones, flexuose. 

 Tamarix gallica. — Broad, far 



apart, widening outward. 

 Pyrus aucuparia, 2 years old . — 



Regular, strongly defined. 

 Rosa canina. — 5 to 10 thin 



ones, lying between thick 



ones. 



Cytisus laburnum, 4 years old. 

 — Mostly very thick, with a 

 few intermediate thin ones. 



Crataegus oxyacantha, 4 years 

 old. — Thin, somewhat evenly 

 disposed. 



Hedcra helix. — Broad rays 

 widening outwards, alternat- 

 ing with intermediate thin 

 ones. 



Other Particulars. 



B. — Edge of Woody Tissue next Pith, 



Syringa vulgaris, 3 years old. — 

 Thin, flexuose. 



Cornus sanguineus, 3 years old. 

 — Strongly defined, with in- 

 termediate thin ones, wavy. 



Ficus carica.- — Wide apart, un- 

 equally distant. 



Corylus avellana, 2 years old. 

 — Thin, crowded. 



Ulmus campestris, 4 years old. 

 — Strongly defined, wide 

 apart. 



Ulmus campestris, var. subcrosa, 

 2 years old. — As above. 



Morus nigra. — Thick, placed at 

 unequal distances apart. 



Ligustrum vulgare, 5 years old. 

 — Straight and regular, near- 

 ly equidistant and well-de- 

 fined. 



Cotoneaster vulgaris, 3 years 

 old. — Thin, nearly equidis- 

 tant. 



Large and crowded in the 

 lines of annual growth, in- 

 termediate ones small and 

 scattered. 



Disposed in circular bands, 

 abundant, of medium size. 



Wide apart, large, mostly 

 compound. 



Mostly compound, arranged 

 in lines radiating from the 

 pith, with intermediate 

 blank spaces. 



Large, arranged chiefly in 

 parcels in the lines of annual 

 growth. 



Large, sparse, scattered. 



Large, many compound. 



In rings in the lines of annual 

 growth, intermediate ones 

 few and scattered. 



Extremely small, form a ring 

 at edije of each annual zone. 



Liber in a single ring. 



Woody tissue, mottled, epi- 



phlceum corky. 

 Black spots in endophlceum, 



bark thick. 



Liber in distinct parcels. 



Liber abundant in 2 rings of 

 parcels, bark rather thick. 



Curved bundles of liber lying 

 between the extremities of 

 each pair of the broad medul- 

 lary rays. 



Liber in little parcels, wide 

 apart. 



Liber in irregular parcels. 



Liber in small parcels, cells of 

 epiphlceum large. 



even or nearly so. 



1 to 13 J Liber abundant, forming com- 

 plete rings, loose tissue out- 

 side bark. 



1 to 19 Bark rather thick. Liber very 

 sparse. 



I to 5 Certain rings in the woody 

 tissue, containing granules 

 which give them a clouded 

 aspect. 

 I to 71 ' Liber in a ring, and also de- 

 tached parcels. Bark full of 

 crystals. 



1 to 191 Liber abundant in dense rings 



and parcels, endophlceum 



full of crystals. 

 1 to 250 Great development of corky 



tissue in 6 or more parcels. 

 ) 3^ Liber in detached parcels, and 



in a ring. 

 1 to 24 I Liber scanty. 



I to 170 Bark thick. Liber in parcels. 



