GLOSSARY 741 



kinetin 6-furfurylaminopurine. 



leaf-area ratio total leaf area/plant weight. 



lithophytia a class of ecosystem predominantly controlled by the rocky 



substrate. 

 lobopodium the clear c>toplasmic area in certain types of zoospores which 



is capable of ameboid change of shape. 

 M molar. 

 meristem a localized group of embryonic cells which persists throughout 



the life of a plant and produces additional adult tissue. 

 mesenchyme embryonic connective tissue which gives rise to the connec- 

 tive tissues of the body and the blood vessels. 

 mesonephros the excretory organ (or kidney) of the embryo; it is behind 



the pronephros, toward the tail end. 

 metamorphosis a change in shape or structure involving a transition from 



one developmental form to another, as in the insect and frog. 

 monocotyledon a group of plants characterized by the presence of one 



cot\'ledon (seed leaf) in the embryo. 

 monoecium individual plants which produce both staminate and pistillate 



flowers. 

 mutagenesis the process of mutation. 

 mycelium system of fungal hyphae. 

 myxamoebae motile cells of cellular slime molds. 

 NAA naphthaleneacetic acid. 

 net assimilation rate ( unit leaf rate ) the increase in dry weight per square 



centimeter of leaf per week. 

 neurula a stage in the development of the embryo that follows the gas- 



trula. The neural tube appears during this stage. 

 nucleoside a compound composed of a nitrogenous base and a sugar. 

 nucleotide a compound composed of a nitrogenous base, a sugar, and a 



phosphate. 

 nutrilite a nutritional element. 

 ONPG orthonitrophenolgalactoside. 

 orchidectomy surgical removal of the testes. 

 osteogenesis formation of bone. 

 ovine pertaining to sheep. 



oxyphytia a class of ecosystem predominantly controlled by acid substrate. 

 (i> X 174 a bacteriophage. 

 perigynous flowers with the sepals, petals, and stamens attached to a 



raised portion of the receptacle so that these parts appear to arise in 



a ring around a partly enclosed ovary. 

 phagocytes cells of the body that ingest microorganisms, other cells, and 



foreign particles. 

 photoperiod a series of relative lengths of day and night which induce 



flowering and other developmental effects. 

 phototropism the response of plant organs to unilateral light. 

 phyllotaxis the arrangement of leaves on a stem. 



