398 



INDEX AND GLOSSARY 



Differentia'tion (dijfero, to carry different 

 ways), explained and illustrated, 34, 119 



Diges'tion (cligero, to arrange or digest), 

 the process by which food is rendered fit 

 for absorption, 12, 13 : intra- and extra- 

 cellular, 232 : contrasted with assimila- 

 tion, 233 



Digestive gland, 317 



Dimorph'ism, dimorph'ic (Si's, twice: 

 /u.op(/>r;, form), existing under two forms, 

 35, 136, 243, 368, 370 



Dioe'cious (Sis, twice : OIKO?, a dwelling), 

 applied to organisms in which the male 

 and female organs occur in different in- 

 dividuals, 199 



DIPH'YES (Si<uvj5, double) : Figure, 252 : 

 occurrence and general characters, 250 : 

 polymorphism, 251 



DiplOblast'iC (SiTrAoo?, double : /SAaaro?, a 

 bud), two-layered : applied to animals in 

 which the body consists of ectoderm and 

 endoderm, 244 : derivation of diploblas- 

 tic from unicellular animals (Figures), 

 266, 268, 269 



Directive sphere, 65, 261, 263. See also 

 Centrosome. 



Disc, Vorticella, 128 



Dispersal, means of : in internal parasite, 

 124 : in lixed organisms, 133-136 



Distal, the end furthest from the point ot 

 attachment or organic base, 126 



Distribution of food-materials : in a 



complex animal, 281 : in a complex 

 plant, 341 



Divergence of character, 145 

 Division of physiological labour, 34 

 DOGFISH : Figure, 326 : general charac- 

 ters, 324 : fins, 324 : exoskeleton, 325 : 

 endoskeleton, 325 : enteric canal, 328 : 

 gills, 329 : blood-system, 329 : kidney, 

 330 : gonads, 330 : nervous system, 330 

 Dry-rigor, stiffening of protoplasm due to 

 abstraction of water, 21 



E 



Echinodermata, the, 308 



Ect'oderm (e/crd?, outside : Se'p;ua, skin), 

 the outer cell-layer of diploblastic and 

 triploblastic animals, 225-230, 278 



Ect'osarc (e/cro?, outside : o-cipf, flesh), the 

 outer layer of protoplasm in the lower 

 unicellular organisms, distinguished by 

 freedom from granules, 4 



Egestlon (egero, to expel), the expulsion 

 of waste matters, 12 



Egg-cell. See Ovum. 



Em'bryo (e^.jSpvoi', an embryo or foetus), 

 the young of an organism before the 

 commencement of free existence. 



Em'bryo-sac. See Megaspore. ^ 



Encysta'tion, being enclosed in a cyst 



(?.?'.) 

 End'oderm (ej/SoV) within : Se'p/xa, skin 



the inner cell-layer of diploblastic and 

 triploblastic animals, 225, 231, 278 



End'oderm-lamella, Medusa, 241 



Endogenous (ei/fioi/, within : yiyvoficu., to 

 come into being), arising from within, 

 e.g. the roots of vascular plants, 354 



End'osarc (evSov, within : <7ap, flesh), 

 the inner, granular protoplasm of the 

 lower unicellular organisms, 4 



Endoskel'eton (evSov, within, and skeleton, 

 from axeAAco, to dry), the internal skele- 

 ton of animals, 325 



End'OSperm(eVSoi', within : crTrep/ixa, seed), 

 nutrient tissue formed in the megaspore 

 of Phanerogams, 377, 383 



Endospore (HvSov, within : a-rropd, a seed), 

 a spore formed within a vegetative cell, 

 89 



Energy, conversion of potential into 

 kinetic, 15 : source of, in chlorophyll- 

 containing organisms, 31 



Enter'iC (eWepov, intestine), canal, the 

 entire food-tube from mouth to anus : 

 Polygordius, 273, 279 : Starfish, 312 : 

 Crayfish, 315 : Mussel, 322 : Dogfish, 328 



Ent'eron or Enteric cavity, the simple 

 digestive chamber of diploblastic ani- 

 mals, 225 



Epidermis (eni upon : Se'p/uer, the skin) : 

 in animals synonymous with deric epi- 

 thelium {q.v. , under Epithelium) : in vas- 

 cular plants a single external layer of 

 cells, 348, 352, 353 



Epithelial cells : columnar, 58 : ciliated, 



59 



Epithelium (ri, upon : 0T?Ayj, the nipple), 

 a cellular membrane bounding a free 

 surface, 246 : coelomic, 277, 304 : deric, 

 272 : enteric, 276, 278 



Equatorial plate, 67 



EQUISETUM (equus, a horse: seta, a 

 bristle : Figure, 367 : general charac- 

 ters, 366 : cone and sporophylls, 366 : 

 male and female prothalli, 366, 367 : al- 

 ternation of generations, 367, 368 



Equiv'ocal generation. See Abiogenesis. 



EUGLEN'A ( euyATjvos, bright-eyed) : 

 Figure, 45 : occurrence and general 

 characters, 44 : movements, 44 : struc- 

 ture, 45 : nutrition, 46 : resting stage, 

 47 : reproduction, 48 : animal or plant 1 

 178 



Euglen'oid movements, 45 



Evolution (evolvo, to roll out), organic : 



definition, 143 : illustration of in connec- 

 tion with species of Zoothamnium (Dia- 

 gram), 144 



Excre'tion (excerno, to separate), the 

 separation of waste matters derived from 

 the destructive metabolism of the or- 

 ganism, 16, 284 



Exogenous (e, out of: yi'-yt/o/u.ai, to come 

 into being), arising from the exterior, 

 ?.. leaves, 354 



