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 Biogenesis. 

 Life-hiStorj, meaning of the term, 43 

 Lignin (li&nnm, wood), composition and 



properties of, 416 

 Ligule, 443 

 Linear aggregate, an aggregate of cells 



arranged in a single longitudinal series, 



188 



Linnaeus, C., introducer of binomial no- 

 menclature, 8, 139 

 Liver, Dogfish. 382 

 Lymphatics, Dogfish, 391 



M 



Mad'reporite (from its similarity to a 

 madrepore or stone-coral), 308 



Mandible, 324 



Mantle, Mussel, 34 8 



Manub rium (mannbrinm, a handle) of 

 Medusa, 239 



Maturation of ovum, 259 



Maxilla, 324 



Maxilliped (maxilla, jaw ; pes, foot), 



3 2 3 



Maximum temperature of amoeboid 

 movements. 21 



Medulla or Medullary substance (me- 

 dulla, marrow): in Infusoria, not in 

 Gymnosnerms, 448 



Medullary rays, 449, 452 



Medus'a (Mefiovo-a, name of one of the 

 Gorgons), the free-swimming reproduc- 

 tive zooid of a hydroid polype, 239: 

 derivation of a, from hydranth (Figure), 

 240 



Medus'oid, a reproductive zooid having 

 the form of an imperfect Medusa, 

 Diphyes, 249 



Meg'agam'Ote (/ae'yas large : ya/u.ew to 

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

 guished by its greater size from the male 

 or microgamete, 132 



Meg anucleus (n-fya.<; large ; nucleus, a 

 kernel), in, 128 



Meg asporan'gium (/aeya? large : <nropa 

 seed : ayyeloi/ a vessel), the female 

 sporangium in plants with sexuilly di- 

 morphic sporangia, usually distinguished 

 by its greater size from the male or 

 micro-sporangium : Salvinia, 440 : Sela- 

 ginella, 411 : Gymnosperms, 455 : Angio- 

 sperms, 466. 



Meg'aspore Oxe-yas, large t o-nopd, 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 t Angiosperms, 466 



Megazo'oid (juu'ycu; large : wov, animal : 



elfio?, form), the larger zooid in unicel- 

 lular organisms with dimorphic zooids. 

 35, 132 



Mer'lstem (joiepurrrj/uia, formed from 

 /uepi'tjou, to divide), indifferent tissue of 

 plants from which permanent tissues are 

 differentiated, 418 



Mes'enteiy (^e'o-os, middle t ei/repoc, in- 

 testine), a membrane connecting the en- 

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

 velopment of, 301 



Mes'oderm (/aeo-os, middle t 6e'pM, skin), 

 the middle cell-layer of triploblastic 

 animals t Polygordius, 275 : develop- 

 ment of, 296 : splitting of to form somatic 

 and splanchnic layers, 299 



MesoglCB a (jxeVos, middle : -yAoia, glue), 

 a transparent layer between the ecto- and 

 endo-derm of Coel~nterates : in Hydra, 

 222 : in Bougainvillea, 236, 240 



Mes'ophyll (fjiecro?, middle : <f>v\\ov, a 

 leaf), the parenchyma of leaves, 420 



MBS estates (/u.e<ros, middle : oTTJi/ai, to 

 stand), intermediate products formed 

 during metabolism (q.v.) and divisible 

 into (a) anabolic mesostates < r ana- 

 states, products formed during the con- 

 version of food-materials into proto- 

 plasm ; and (b) katabolic mesostates 

 or katastates, products formed during 

 the breaking down of protoplasm, 18 



Metabolism (^erafto^, a change), the 

 entire series of processes connected with 

 the manufacture of protoplasm, and 

 divisible into (a) constructive meta- 

 bolism or anabolism, the processes by 

 which the substances taken as food are 

 converted into pro'oplasm, 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 (/u-e'ra, after : /ne'pos, 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 (/u.eTa/i6p<f>w<rts), a trans- 

 formation applied to the striking change 

 of form undergone by certain organisms 

 in the course of development after the 

 commencement of fr> e existence : Vor- 

 ticella, 133 t Polygordius, 298 t Mussel, 

 365 



MiC robe Oxi/cpbs. small : tos, life). See 

 Bacteria 



MICROCOC'CUS (|ou*cpbs, small t KOKKOS, 

 a berry) (Figure), 86 



Microgam'ete OiiKpbs, small t yaiu.e'w, to 

 marry), a male gamete (q.v.), distin 

 guished by its smaller size from the 

 female or megagamete, 132 



Micro-millimetre, the one-thousandth of 



