SKEAN-DHU 



SKELETON 



483 



Wheeled skates were in use on roads in Holland 

 as far back as 1770 ; but it is only since the intro- 

 duction of the circular running roller-skate, in- 

 vented in 1865 by Mr Plimpton of New York, 

 speed and figure skating have become common on 

 roller-skates. Besides being a means of exercise 

 taken under a fascinating form, roller-skating i> a 

 splendid introduction to ice-skating. 



A bibliography of nearly 300 works relating to skating 

 was printed in Note* and Queries between 1874 and 

 1881. The modern books on ( 1 ) Speed-skating are the 

 Annual Reports of the National Skating Association ; 

 Fen-skating, by N. and A. Goodman (Sampson Low & 

 Co. ) ; Speed-skating, by N. Goodman ( ' All England ' 

 series); Spted -stating, by Heath cote and Tebbutt 

 ( ' Badminton ' series ) : and ( 2 ) on Figure-skating, The 

 Art of Skating, by Cyclos (Horace Cox); A System of 

 Fuinrc-tltaling, by Vendervell and Witham (Horace 

 Cox); Skating Card*, by W. Crossley (L. Upcott Gill); 

 Combined Figure-$kating, by Monier- Williams, Pidgeon, 

 and Dryden ( Horace Cox) ; Skating, by D. Adams ('All 



mantidi and others (A. Holder, Vienna). For skating 

 with sails, see the Badminton book, p. 213. 



Skean-dhu. See DIRK. 



Skeat, WALTER WILLIAM, a learned Early 

 English scholar, was born in London, November 

 21, 1835, and educated at King's College School 

 and Christ's College, Cambridge, graduating as 

 fourteenth wrangler in 1858. He became Fellow 

 of his college in 1860, and four years later 

 Mathematical Lecturer there ; filled for some time 

 curacies at East Dereham and Godalming ; in 

 1878 was elected the first Ellington and Boeworth 

 professor of Anglo-Saxon at Cambridge, and re- 

 elected to a Christ's College fellowship in 1883. 

 He was the first director of the Dialect Society 

 (established 1873), and he has contributed, by his 

 exhaustive labours on Langland and Chaucer, and 

 innumerable editions of Early English works, more 

 than any scholar of his time to a sound knowledge 

 of Middle English and English philology generally. 



His most important books are the following : Piers 

 Plovman, in its three texts ( 5 parts, 1867-85 ; re-issued 

 by the Clarendon Press, 2 vols. 1886 ) ; The Lay of 

 Havelot the Dane (1868); Harbour's Bruce (3 parts, 

 1870-77); Chaucer's Treatite on the Astrolabe (1872), 

 Ac., all edited for the Early English Text Society ; an 

 edition of Chattel-ton's Poems ( 2 vols. 1875); Chaucer's 

 Minor Poena (1888); school editions, for the Clar- 

 endon Press series, of several of Chaucer's Canter- 

 bury Tain, a portion of Piers Plowman, and two 

 volumes of Specimens of earlier English literature; 

 the Kingit Quair (1884), for the Scottish Text Society; 

 A Sftao-aothie Glossary (1868); his great Etymological 

 English Dictionary (1882), and its admirable abridg- 

 ment, the Concise Etymological Dictionary ( 1882 ) ; 

 and Principles of English Etymology, 1887-91); hi great 

 edition of Chaucer (6 vols., Clar. Press, 1894-95) and his 

 Student's Chaucer( 1898 ) ; and A Student's Pastime( 1896 ). 

 See his own bibliography of fifty-two works in Notes and 

 Queries, September 1892. 



Sketfiiess, a little watering-place of Lincoln- 

 shire, 2-2 miles NE. of Boston. Pop. 1488. 



Skeleton, a general term for the more or less 

 hard parts of animal.s, whether forming an internal 

 supporting framework an endoskeleton, or an 

 external exokeleton, often useful as armour. The 

 term includes so many different kinds of structure 

 and material that it U necessary to take a survey 

 of representative types. 



Skeleton of Invertebrates. Many of the Protozoa 

 have shells of lime (see FOEAMINIFERA ), or of flint 

 (see RADIOLARIA), or of some organic substance, 

 such as acanthin. These are formed by the living 

 matter of the units, in the case of the lime and 

 Hint shells from materials absorbed from the sur- 

 rounding water, but in what precise way we do not 



know. Almost all Sponges (q.v.) are supported by 

 loose or firmly fused spicules of lime or of flint, or 

 have, as in the bath-sponge, an interwoven sup- 

 porting skeleton of ' horny ' fibres. The spicules 

 or fibres are formed by cells in the middle stratum 

 of the sponge. Among Ccelenterates various forms 

 of skeleton, both external and internal, both limy 

 and 'horny,' are represented by the different kinds 

 of corals (see CORAL). With few exceptions these 

 skeletons are produced by cells belonging to the 

 outer layer or ectoderm of the animal. Worms 

 have little that can be called a skeleton, although 

 some authorities would compare the sheath of the 

 proboscis in Nemertea (q.v.) to the notochord of 

 Vertebrates. The tubes, calcareous or otherwise, 

 in which many sedentary worms are sheltered, 

 have no vital connection with the animals which 

 make and inhabit them. Echinoderms tend to be 

 very calcareous ; lime is deposited in the mesoder- 

 mic tissue of the body in almost any part, though 

 predominantly near the surface. Most Arthropods 

 have well-developed exoskeletons, cuticles formed 

 from the epidermis, consisting in great part of an 

 organic basis of chitin, on which, in Crustaceans 

 and most Myriopods, carbonate of lime is also de- 

 posited. As tliis cuticle is not always restricted 

 to the outside of the animal, but sometimes extends . 

 inwards, an apparent endoskeleton arises e.g. in 

 the lolter, the king-crab, and the scorpion. Most 

 Molluscs have shells in which carbonate of lirne 

 occurs along with an organic basis conchiolin, and 

 in cuttle-fish there is a remarkable development of 

 cartilage around the nerve-centres in the head an 

 analogue of the skull in Vertebrate animals. From 

 this rapid survey it will be seen that the skeletons 

 of Invertebrates are very varied alike in structure 

 and in composition ; if we except a few doubtful 

 hints of a supporting axis, there are no bomologies 

 between the skeletons of Invertebrates and Verte- 

 brates ; to the latter, moreover, that form of tissue 

 which we call bone is exclusively restricted. 



Skeleton of Vertebrate*. Here we must distin- 

 guish first of all between the external exoskeleton 

 and the internal endoskeleton. The scales of 

 fishes, the scales and scutes of reptiles, the scales, 

 claws, and even feathers of birds, the remarkable 

 Ixmy armature of armadillos, the scales of pan- 

 golins, the claws of carnivores, the quills of porcu- 

 pines, and even the hair of ordinary mammals 

 illustrate the variety of structures which may be 

 included within the anatomical conception of an 

 exoskeleton. All these structures are formed in 

 the epidermis, or in the dermis, or in both com- 

 bined. Tortoise-shell and the scales of reptiles are 

 epidermic ; the scutes of crocodiles and the plates 

 covering armadillos are dermic ; the scales of 

 Elasmobranch and Ganoid fishes are due to both 

 layers. But it is difficult to carry out any rigidly 

 logical classification. Thus, the dorsal shield of a 

 tortoise is physiologically an exoskeleton, but 

 structurally it is in great part formed from the 

 dorsal vertebrae and from what in other animals 

 form the ribs. The ventral shield of a tortoise is 

 formed from dermal bones, and the so-called abdo- 

 minal ribs of crocodiles arise as ossifications in the 

 fibrous tissue which lies underneath the skin and 

 above the muscles. The teeth of Elasmobranch 

 fishes are undoubtedly homologous with the dermal 

 denticles or skin-teeth which occur over the skin, 

 and the teeth of mammals are started by enamel 

 germs which sink in from the epidermis of the 

 mouth. 



The Vertebral Column. In a primitive Verte- 

 brate animal like the lancelet the body is supported 

 by a median dorsal axis, and, apart from slight 

 support* for the mouth, the pharynx, and the 

 median fin, this is all the skeleton. The median 

 dorsal axis, which in the lancelet has not even the 



