SARCOPTES. 



[ 561 ] 



SARCOSCYPHUS. 



Infusoria, placed alive in water between two 

 plates of glass. In the course of a short 

 time, the outline of the bodies of the animals 

 is seen to be bordered with a row of project- 

 ing diaphanous globules (PI. 25. fig. 2 a), 

 frequently more or less pressed together, 

 which after a time become separated and 

 float in the liquid, especially if it be shaken. 

 Spherical cavities or vacuoles are soon per- 

 ceptible in these globules of sarcode (PI. 25. 

 fig. 2 b), the nature of which is readily de- 

 termined by comparing the refi'action of the 

 hght at their circumference with that at the 

 circumference of the globules themselves; 

 for on elevating the object-glass, the centre 

 of the vacuoles becomes darker, and the 

 centre of the globules becomes brighter; 

 whilst on approximating the object-glass, 

 the reverse takes place. The spontaneously 

 produced cavities or vacuoles continue to 

 enlarge and increase in numbers, until some 

 of them appear perforated in all directions. 

 Ultimately the globules become so altered 

 by the action of the water, that they form a 

 thin granular or wi-inkled layer, resembling 

 coagulated albumen. 



The protoplasm of vegetable cells appears 

 to correspond to the sarcode of animal struc- 

 tures. In certain cells it exists in two forms 

 as regards density, the outer portion being 

 firmer than the inner; or it may become 

 entirely liquid. In many of the lower or- 

 ganisms, and probably most cells in their 

 youngest state, it is glutinous, and in the 

 former permanently remains so. 



When existing in cells and the lowest ani- 

 mals, it appears to constitute the essential 

 part of their structure, and is capable of per- 

 forming all the functions carried on by the 

 tissues of the higher or more peifect or- 

 ganisms. It also appears that the cell- 

 theory, insofar as it attributes the principal 

 importance to the cell-wall, is founded upon 

 error; the cell-wall merely forming a pro- 

 tection to the sarcode or primordial utricle 

 of plants, and the sarcode or protoplast as 

 it might be called of animals, enabling them 

 to carry on their essential functions uninter- 

 rupted by surrounding influences. 



BiBL. Dujardin, Infus. p. 35. 



SARCOPTES, Latr.— A genus of Arach- 

 nida, of the order Acarina, and family 

 Acarea. 



S. scabiei {Acarus scabiei) (PI. 2. fig. 16). 

 The itch-insect of man. 



Body soft, white, oval-oblong or rounded ; 

 ventral surface with transverse and undula- 

 ting rugae ; dorsal surface with marginal 



irregularly concentric rugae, the central 

 space with numerous short and conical 

 papillae, and stouter but short protuberances 

 or spines arising from an annular base ; at 

 the sides and upon the surface of the body 

 are also scattered setae. Head small, some- 

 what narrowed in front ; mandibles toothed. 

 Anterior two pairs of legs separated from 

 the posterior by a considerable interval ; 

 legs short, the anterior two pairs with aceta- 

 bula or adhesion-disks and five-jointed, the 

 posterior three-jointed, the last joint termi- 

 nated by a long seta and without acetabula. 

 Length of female 1-100 to 1-/5". 



The females burrow in the skin, in which 

 the oval eggs, 1-120" in length, are laid; 

 these are hatched in about ten days, and the 

 young have only six legs. 



Male onlv about half the size of the female, 

 and with acetabula to the hindermost pair of 

 legs. 



There is no question that the irritation 

 produced by these mites and their ova is the 

 cause of the itch. 



They should be searched for at the bottom 

 of one of the burrows, which are often 

 visible to the naked eye; the ova are fre- 

 quently present in the pustules. They are 

 most easily found by examining the skin 

 with a power of fifty to seventy diameters, 

 attached to a firm but moveable arm, and 

 with the aid of a good bull's-eye con- 

 denser. 



The entire animals may be preserved in 

 glycerine or solution of chloride of calcium ; 

 the parts of the mouth should be dried and 

 mounted in Canada balsam. 



Other imperfectly examined or doubtful 

 species occur upon animals, as the drome- 

 dary, the chamois, the dog, sheep, rabbit, 

 &c. 



See Demodex and Psoroptes. 



BiBL. Bourguignon, Traite, Sfc, de la gale 

 (abstract in ^fZ. Monthly Joiirn. 1852. Ix.); 

 Gervais, Walckenaer^s Insect. Apteres, iii. 

 268, and Ann. d. Sc. nat. xv. 9 ; Hering, 

 D. Kr'dtzmilben d. Thiere, Nov. Act. nat. 

 cur. xviii. 573 ; Duges, Ann. d. Sc. nat. 

 2 ser. iii. 245; Wedl, Pathol. Histnlog. 

 798 



SARCOSCYPHUS, Corda.— A genus of 

 Jungermannieae (Hepaticaceae). S. Ehrharti 

 {Jung, emarginata, Ehrh.) is a remarkable 

 species, of dark purple, almost black colour, 

 growing frequently in wet places, on rocks 

 of mountainous districts. 



BiBL. Hook. Brit. Flor. ii. pt. 2. p. 114, 

 Brit. Jung. pi. 27 ; Ekart, Synops. Jung. 



2o 



