GLOSSARY 387 



Loligo {loW go). A genus of cuttlefishes (mollusks) similar to Sepia; commonly 



called squids. 

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

 Lumbar {lum' bar). Pertaining to the loins, the region of the back posterior to the 



ribs. 

 Lumbricus terrestris (lum hri' kus ter res' tris). A species of earthworm. 

 Lung (lung). A respiratory organ in the vertebrates. 

 LyeU, Sir Charles (^^' el). A British geologist, 1797-1875. 

 Lymnaea (Um ne' a) . A genus of snails. 

 Lymph (limf). A clear fluid containing colorless cells found in lymph vessels. It is 



essentially blood without its red cells and somewhat diluted. 

 Lymphatic system {Urn fat' ik sis' tern). A system of vessels conveying lymph in 



vertebrates. 

 Lymph heart {limf hart'). One of a number of contractile chambers in the lymphatic 



system of lower vertebrates which by their pulsation propel the lymph. 



Macrogamete {mak' ro gam' eet). The larger one of two kinds of gametes in species 



in which these cells differ in size. 

 Macronucleus {mak' ro nu' kle us). The large nucleus in a cell or organism having 



two nuclei of unequal size. 

 Macrosiphum sanbomi {mak' ro si' fum san' born i). A species of insect, one of the 



plant lice, living on chrysanthemum plants. 

 Malpighi, Marcello {mahl pee' gee). ItaUan anatomist, founder of microscopic anat- 

 omy, 1628-1694. 

 Malpighian corpuscle {mahl pee' gee an kor' pv^ s'l). One of numerous bodies in 



the kidneys of vertebrate animals, each composed of the expanded end of a 

 kidney tubule (Bowman's capsule) and an enclosed knot of blood capillaries 



(glomerulus). 

 Maltase {mawV tase). An enzyme splitting maltose into glucose. 

 Malthus, Thomas Robert {mal' thus). EngHsh political economist, author (1803) of 



" Essay on Population," who lived 1766-1834. 

 Maltose {mawV lose). Malt sugar. 

 Mammal {mam' mal). One of the MammaUa. 

 Mammalia {mam ma' lia). 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 {mam mal' oji). The zoology of mammals. 

 Mammoth {mam' muth). An elephant-like animal of prehistoric times. 

 Manatee {man' a tee'). An aquatic mammal of the order Sirenia, commonly called 



sea-cow. 

 Mantle {man' VI). A sheet of tissue, typically quite thin, which secretes the shell in 



mollusks. 

 Manubrium {ma nu' bri um). A projection from the center of the sub-umbrella 



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



mouth at its end. 

 Marginal bone {mar' jin al). One of a ring of bones around the margin of the cara- 

 pace of a turtle. 



