GLOSSARY OF TECHNICAL TERMS xxvii 



JURASSIC, one of the subdivisions of the mesozoic era, the 



characteristic rocks of which are greatly developed in the 



Jura mountains. 

 KABYOGAMY (Gr. Kapvov, nut, used for nucleus ; ydjuos, marriage), 



the fusion of nuclei in conjugation. 

 KARYOKINESIS (Gr. Kapvov, nut, nucleus ; KU^CTIJ, movement), 



another term for mitosis (q.v.). 

 KARYOPLASM (Gr. Kapvov, nut, nucleus ; TrAdcr/xa, formative material), 



the protoplasm of the nucleus. 

 KARYOSOME (Gr. Kapvov , nut, nucleus ; o-oijita, body), a special 



aggregation of chromatin in the resting nucleus. 

 KATABOLISM (Gr. Kara^oArj, a throwing down), a term applied to 



all the destructive chemical processes which go on in the 



living body, resulting in the formation of waste products. 

 LABYRINTHODONTS (Gr. \afivpivdos, labyrinth ; obovs, tooth), a 



group of extinct amphibians, so-called from the pattern of 



the teeth. 

 LARVA (Lat. larva, ghost, mask), an immature but more or less 



active stage in the development of certain animals, differing 



widely in appearance from the adult. 

 LEGUMIN (Lat. leyumen, pulse), a proteid substance found in peas 



and beans. 



LEUCOCYTE (Gr. \CVKOS, white ; KVTOS-, cell), a white blood corpuscle. 

 LININ (Gr. \LVOV, thread), an achromatic substance which forms 



a network of threads in the nucleus. 

 LYSIN (Gr. ATATI?, breaking up), a chemical substance which 



brings about the disintegration of cells. 

 MALIC ACID (Lat. malum, apple), an organic acid found in sour 



apples and other fruit. 

 MAMMAL (Lat. mamma, breast), a vertebrate animal which suckles 



its young. 

 MANUBRIUM (Lat., handle), the projection on which the mouth 



is placed in a jelly fish. 

 MEDUS/E (Lat. Medusa, the Gorgon), jelly fish, the sexual 



individuals of certain hydroids. 

 MEGAGAMETES (Gr. /xe'yas, large ; ya/xeY???, spouse), the large (female) 



gametes, where the latter are differentiated into two sizes. 

 MEGALECITHAL (Gr. jue'ya?, large ; \c*i0os, yolk, lit. porridge), a 



term applied to eggs which contain much yolk. 

 MEGANUCLEUS (Gr. ^yas, large ; Lat. nucleus, kernel), the larger 



(somatic) nucleus in Paramcecium, &c. 



