406 BIOLOGY 



lacunae. Spaces among the tissues in which lymph collects, 192, 208. 



L..MARCK, 350. 



Lamarckian factors. Forces in evolution first suggested by Lamarck, 



351. 



lamella. A thin plate or layer, 

 larva. A free-living stage in the development of an animal, unlike the adult, 



e. g., a tadpole, 286, 289. 

 larval history. The stages in the life history of an animal after hatching 



from the egg and before adult form is reached, 

 larynx. The enlargement of the air passages containing the vocal cords, 



191, 209. 



leaf, structure of, 114. 



legumen. A proteid derived from legumes, 8. 

 legumes. Plants belonging to the Leguminosae family, like beans, peas, 



clover, alfalfa, vetches, locusts, etc. 

 Leucanthemum, 345. 

 leucocytes (Gr. leukos = white -f- cytos = cell). The white corpuscles of 



the blood, 192, 205. 

 lichens. The grayish green mosses which grow on rocks or trees, etc.; an 



association of a fungus and a green plant, 229. 

 life cycle. See generation; of nature, 234. 

 life force, 4, 323. 



ligaments. Bands of connective tissue connecting bones, 184. 

 lingual (Lat. lingua = tongue). Pertaining to the tongue, 190. 

 linin. The delicate fibers extending through the karyoplasm and forming 



a network, 32. 



littoral. Pertaining to the shore. 



liver. A large gland opening into the intestine at the pylorus, 186. 

 lophotrichic (Gr. lophos = a crest + thrix = hair). With a tuft of fla- 



gella, 81. 



low organisms. Organisms with a simple structure, 96. 

 lumen. A cavity in a tube or sac. 

 lungs, 191, 209. 



lymph. The liquid part of the blood after it has passed out of the capilla- 

 ries into the tissues, 176, 192, 208. 

 lymph glands. Glandular swellings on the lymph vessels, which belong to 



the ductless glands; lymph nodes, 192. 

 lymph hearts. Four pulsating sacs in the frog, that force lymph into the 



veins, 192, 208. 



lymph spaces. Spaces in tissues in which lymph collects, 176. 

 lymph vessels. Tubes carrying lymph from the lacunae to the veins, 192, 



208. 



