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GLOSSARY. 



special organs for special work, 

 as the specialization of the 

 hand of man from the fore- 

 foot of other mammals ; also 

 applied to tlie special develop- 

 ment during embryonic life of 

 parts adapted for peculiar or 

 special functions. 



Digit. A finger or toe. 



Di-iriD'i-ATE. Half round. 



Di-cE'ci-ors. (Gr. dis, two; 

 oikoa, house). With distinct 

 sexes. 



Dip'te-ba (6r. dis, two; pteron, 

 wing). Two-winged flies ; an 

 order of insects. 



Di-vEK-Tic'r-LUii. An offshoot 

 from a vessel or from the ali- 

 mentary canal. 



Duct. A tube or passage usu- 

 ally leading from glands. 



Ec-DTSis (Gr. ekdum, casting 

 off). The process of casting the 

 skin ; moulting. 



E CHHT-o-DEil'MA-TA (Gr. ecMnos, 

 a hedgehog or urchin ; hence 

 applied to the sea-urchin ; and 

 derma, skin). The fourth sub- 

 kingdom of animals. 



E LAS-MO-BRAxcHi-i (Gr. elosma, 

 a strap; bragchia, gill). The 

 sharks and rays. 



E-la'tek. The spring or forked 

 "tail" of Podurans. 



E-LTTBA (Gr. elutron, a sheath). 

 The fore-wings of beetles, 

 serving to cover or sheathe the 

 hind wings. 



Em'bbt-o. The germ or young 

 animal before leaving the egg 

 or body of the parent. 



Endoblast. The primitive, 

 embryonic endoderm. 



Ente-bon (Gr. enteron). A gen- 

 eral term applied to the diges- 

 tive canal as a whole. 



E-PHEii'E-Ei-5A. The order of 

 net-veined insects represented 

 by Ephemera. 



E-Pi blast. The ectoderm in 

 its embryo state. The ecto- 

 blast. 



E-pibo le. TThere the gastrula 

 is formed by a spreading' of a 

 thin layer of epiblast cells 

 over the much larger h}'poblast 

 cells. 



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

 face of flies situated between 

 the front and the labrum. 



E-qn-LAT E-EAL. Having the 

 sides equal, as in Brachiopod 

 shells. 



E Qn-TALVE. Applied to shells 

 like the clams and most La- 

 mellibranchs, which are com- 

 posed of two equal pieces or 

 valves. 



Ex see'ted. Protruded; opposed 

 to enclosed. 



Ex-r'n-riL Cast-ofE skin. 



Fis-sip'A-Eors (Lat. fissug, cleft ; 

 pario, 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. 



FcETUS. The embryo of a 

 mammal. 



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

 ing or lump). A centre of 

 the nervous system, consisting 

 of nerve-cells and fibres. 



Gem-mipa-rous {gemma, bud ; 

 pario, to bring forth). Ap- 



