496 



INDEX AND GLOSSARY 



tides by, 58 : fission of, 58 : formation 



of Plasmodia by, 58 

 Leuwenhoek;, Anthony van, discoverer 



of Bacteria, 97 

 Life, origin of See Hioeenesis. 

 Life-history, meaning of the term, 43 

 Ug^in (lignum, wood), composition and 



p^ope^tle^i of, 416 

 Llgule, 44 ^ 

 Linear aggregate, an aggregate of cells 



arraniijed in a single longitudinal series, 



188 

 Unnans, C, introducer of binomial no- 

 menclature, 8, 139 

 Liver, Dogfish. 382 

 LymphatlOB, Dogfish, 391 



M 



Mad'reporite (from its similarity to a 



madrepore or stone-coral), 308 

 Mandible, 324 



Mantle, Mussel, 348 



Manub rlum (manubrium, a handle) of 



Mfil.isa, 239 

 Maturation of ovum, 359 

 Maxilla. 324 

 Mazllllped {maxilla, jaw ; pes, foot), 



MaTtmnm temperature of amoeboid 

 movements. 21 



Medulla or Medullary substance {me- 

 dulla, marrow): in Infusoria, no: in 

 (iyinnosucrins, 448 



Medullary rays, 449, 453 



MedUS a (Mf'iovo-a, name of one of the 

 (Jorgoiis), the frce-swimniing reproduc- 

 tive zooid of a hydroid polype. 239: 

 derivation of a, from hydranth (Figure), 

 240 



Medus'old, a reproductive zooid having 

 the form of an imperfect Medusa, 

 Diphyes, 249 



Meg'agam'ete (ficyat large : yaitiio to 

 marry), a female gamete (g.v.) distin- 

 guished by its greater size from the male 

 or microgamete, 132 



Meg anucleus (M'yav large ; nudeus, a 

 kf-rntl), III, 128 



Meg asporan glum (M«'yas large : inropa 

 .seed : ayyelov a vessel), the female 

 sporangium in plants with sexually di- 

 morphic sporangia, usually distinguished 

 by Its greater size from the male or 

 micro-sporangium : — .Salvinia, 440 : .Seja- 

 ginella, 411 : Gymiiosperms, 455 : Angio- 

 sperms, 466. 



Meg'aspore {lityii, large : a-wopa, a seed), 

 the female spore in plants with sexually 

 dimorphic spores, always distinguished 

 by its large size from the male or micro- 

 spore :— Salvinia, 440: Selaginella, 441 : 

 Gymnosperms, 455 : Angiosperms, 466 



MegazO'Oid (M<yaf large ; ^wof, animal : 



tlSot, form), the larger zooid in unicel- 

 lular organisms with dimorphic zooids, 

 35> 132 



Mer'lStem (/xeptVnifxa, formed from 

 litpi^ui, to divide), indifferent tissue of 

 plants from which permanent tissues are 

 (lifTerentiated, 418 



Mesentery (^('(rof, middle : ivrtpov, in- 

 testine), a membrane connecting the en- 

 teric canal with the body-wall, 276 : de- 

 velopment of, 301 



Mesoderm (fieVot, middle : Stpiia., skin), 

 the middle cell-layer of triploblastic 

 animals : Polygordius, 275 : develop- 

 ment of, 296: splittingof 10 form somatic 

 and splanchnic layers, 299 



MesoglOB'a (^co-ot, middle : ykoia, glue), 

 a transparent layer between the ecto- and 

 endo-derm of t!u!l-nterate» : — in Hydra, 

 223 : in Rougainvillea. 236, 240 



Mes'ophyll (fxto-ot, middle : ^vWov, a 

 lial), the parenchyma of leaves, 420 



MeS'oStateS (^ro-ot, middle : <rT7Ji'at, to 

 stand), intermediate products formed 

 during met.ibolisin {tj.T.) and divisible 

 into (>i) anabolic mesostates < r ana- 

 states, products formed during the con- 

 version of food-materials into proto- 



)>lasm ; and {h) kataboUo mesostates 

 or katastates, products formed during 

 the brc.iking down <if protoplasm, 18 



Metabolism (fi«Ta/3oA>i, a change), the 

 entire series of processes connected with 

 the manufacture of |iroto|ilasin, and 

 divisible into (a) constructive meta- 

 bolism or anaboUsm, the processes by 

 which the substances taken as food are 

 converted into protoplasm, and {b) de- 

 structive metabolism or katabolism, 

 the processes by which the protoplasm 

 breaks down into simpler products, ex- 

 cretory or plastic, 17 



Met'amere (^(Va, after : nepo^, a part), a 

 body-segment in a transversely seg- 

 mented animal such as Polygordius, 268 : 

 development of, 299 : limited num- 

 ber and concrescence of in Crayfish, 320 : 

 in Dogfish, 372, 377, 396 



Metamorphosis (ixtraiJioptbuxrii), a trans- 

 formation apolied to the striking change 

 of form undergone by certain organisms 

 in the course of development after the 

 commencement of free existence : — Vor- 

 ticella, 133 : Polygordius, 298: Mussel, 

 365 



MlC robe (niKphi, small : ^Jos, life). See 

 Hacteria 



MICROOOC CUS (fiiKpoi, small : kokkos, 

 a berry) (Figure), 86 



Microgamete (fiixpot, small : yaiiiia, to 

 marry), a male gamete (y.z/.), distin- 

 guished by its smaller size from the 

 female or nieg.aKamete, 132 



Mlcro-mlUimetre, the one- thousandth of 



