692 



GLOSS ART. 



special organs for special work, 

 as the specialization of the 

 hand of man from the fore- 

 foot of other mammals ; also 

 applied to the special develop- 

 ment during embryonic life of 

 parts adapled for peculiar or 

 special functions. 



Dig'it. a finger or toe. 



Dimid'i-atb. Half round. 



Di-ce'ci-ous. (Gr. dis, two; 

 oikos, house). With distinct 

 sexes. 



Dip'tb-ra (Gr. dis, two; pieron, 

 wing). Two-winged flies ; an 

 order of insects. 



Diver-tic'u-litm:. An offshoot 

 from a vessel or from the ali- 

 mentary canal. 



DtTOT. A tube or passage usu- 

 ally leading from glands. 



Ec-dt'sis (Gr. eJcdusis, casting 

 off). The process of casting the 

 skin ; moulting. 



Echin-o-dbk'ma-ta (Gr. ecldnos, 

 a hedgehog or urchin ; hence 

 applied to the sea-urchin ; and 

 derma, skin). The fourth sub- 

 kingdom of animals. 



Elas-mo-bban'chi-i (Gr. elasma, 

 a strap; bragchia, gill). The 

 sharks and rays. 



E-ea'tee. The spring or forked 

 "tail "of Podurans. 



E-ly'tka (Gr. elutron, a sheath). 

 The fore-wings of beetles, 

 serving to cover or sheathe the 

 hind wings. 



Em'bry-o. The germ or young 

 animal before leaving the egg 

 or body of the parent. 



Endo-blast. The primitive, 

 embryonic endoderm. 



En'tb-ron (Gr. enieron). A gen- 

 eral term applied to the diges- 

 tive canal as a whole. 



E-phbm'b-ri-na. The order of 

 net-veined insects represented 

 by Ephemera. 



E'-pi-BLAST. The ectoderm in 

 its embryo state. The ecto- 

 blast. 



E-pib'o lb. Where the gastrula 

 is formed by a spreading of a 

 thin layer of epiblast cells 

 over the much larger hypoblast 

 cells. 



E-pis'to-ma. That part of the 

 face of flies situated between 

 the front and the labrum. 



E-qui-lat'e-ral. Having the 

 sides equal, as in Bracliiopod 

 shells. 



E'qui-valvb. Applied to shells 

 like the clams and most La- 

 mellibranchs, which are com- 

 posed of two equal pieces or 

 valves. 



Ex-ser'ted. Protruded; opposed 

 to enclosed. 



Ex-tj'ti-tim:. Cast-off skin. 



Pis-sip' A-Rors (Lat. Jiasus, cleft ; 

 pano, to bring forth). Ap- 

 plied to a form of asexual gen- 

 eration where the parent splits 

 into two parts, each part be- 

 coming a new individual. 



Fce'tus. The embryo of a 

 mammal. 



Gang'li-on (Gr. gagglion, a swell- 

 ing or lump). A centre of 

 the nervous system, consisting 

 of nerve-cells and fibres. 



Gem-mip'a-rous (gemma, bud ; 

 pario, to bring forth). Ap- 



