GLOSSARY 387 



Leptinotarsa {lep' tin o tar' sa). A genus of leaf-eating beetles to which the common 



potato beetle belongs. 

 Leptodactylus (lep' to dak' ti lus). A genus of frogs. 

 Lernaeopoda {ler' ne op' o da). A copepod (Crustacea) parasitic on the gills of certain 



fishes. 

 Leucocyte. A white blood cell. 

 Linear. Arranged in a line or row. 



Lingula. A genus of brachiopods, a group of uncertain relationships. 

 Linkage. The occurrence of the genes for two or more hereditary characters in the 



same pair of chromosomes. 

 Linnaeus, Carolus {lin ne' us). Swedish botanist and naturalist, author of the 



binomial system of nomenclature and an artificial classification of animals and 



plants, 1707-1778. 

 Lipid {Up' id). Any organic compound of the class including true fats, and the 



compounds of fats with other substances such as phosphates and sugars. 

 Liver. A gland which secretes bile and other substances. 



Loxoceras {loks os' er as). A genus of extinct cephalopods of the orthocone type. 

 Lumbar. Pertaining to the loins, the region of the back posterior to the ribs. 

 Lumbricus terrestris {lum bri' kus). A species of earthworm. 

 Lung. A respiratory organ in the vertebrates. 

 Lycopod (W ko pod). A club moss. 

 Lyell, Sir Charles. British geologist, 1797-1875. 



Lymph. A clear fluid containing colorless cells found in lymph vessels. It is essen- 

 tially blood without its red cells and with much less of the proteins. 

 Lymphatic system. A system of vessels conveying lymph in vertebrates. 

 Lymph capillaries. The smaller vessels of the lymphatic system. 

 Lymph node. A connective tissue enlargement in a lymph vessel, which removes solid 



materials from the lymph and produces one kind of white blood cell. 



Macronucleus. The large nucleus in a cell or organism having two nuclei of unequal 



size. 

 Macrosiphum sanborni (niak' ro si' fum). A species of insect, one of the plant lice, 



living on chrysanthemum plants. 

 Malpighi, Marcello {mahl pee' gee). Italian anatomist, founder of microscopic 



anatomy, 1628-1694. 

 Malthus, Thomas Robert. English political economist, author (1803) of Essay on. 



Population, who hved 1766-1834. 

 Maltose. Malt sugar. 

 Mammal. One of the Mammalia. 

 Mammalia. A class of vertebrates having hairy bodies, producing young within the 



body of the mother, and nourishing the young after birth with milk secreted by 



the mother. 

 Mammalogy. The zoology of mammals. 

 Mammoth. An elephantlike animal of prehistoric times. 



Mantle. A sheet of tissue, typically quite thin, which secretes the shell in mollusks. 

 Mantle fibers. Fibers lying about the periphery of the spindle of a dividing cell 



and extending from the centrioles to the chromosomes. 

 Manubrium {ma nu' bri xim). A projection from the center of the subumbrella of a 



medusa, corresponding to the hypostome of a hydranth, and bearing the mouth 



at its end. 

 Marginal bone. One of a ring of bones around the margin of the carapace of a 



turtle. 



