330 GLOSSARY 



intracellular, intrd seVu lar (L. intra, within), existing or done inside of a 

 cell. 



intussusception, in'tususep'shon (L. intus, within; susceptus, taken up), 

 the addition of new particles among the preexisting particles of proto- 

 plasm. 



irritability, ir'ita biPiti (L. irritare, excite), the property of responding to 

 stimuli. 



karyoplasm, kar'i o plazm (Gr. karuon, nucleus ; plasma, a thing formed), 



the substance of the nucleus. 

 karyosome, kar'iosom (Gr. karuon, nucleus ; soma, body), nucleoli which 



stain with nuclear dyes. 

 katabolism, katatfolizm (Gr. katabole, a throwing down), the process by 



which protoplasm breaks down into simpler products. 



larva, lar'va (L. larva, a ghost or mask), the young of any animal which 



during its development is unlike its parent. 

 lateral, lat'e ral (L. latus, side], of or pertaining to the side. 

 Lumbricus, lum bri'kus (L. lumbricus, earthworm), a genus of worms. 



macrogamete, mat?rdgam!et (Gr. makros, long; gamete, wife), a large re- 

 productive cell, the egg. 



macromere, mak'ro mer (Gr. makros, long ; mt-ros, a part), the larger cells 

 in the early embryonic stages of certain animals. 



macronucleus mak ro nfi'kle us (Gr. makros, long ; nucleus), a large nucleus 

 in certain Protozoa. 



maturation, matil ra'shon (L. maturare, ripen), the ripening of the egg by 

 the formation of polar bodies. 



maxilla, mak sit a (L. maxilla, a jaw), an appendage near the mouth of 

 arthropods. 



maxilliped, mak sil'i fed (L. maxilla, a jaw ; pedes, foot), a footlike append- 

 age near the mouth of certain arthropods. 



medusa, tnedu'sa (L. Medusa, a mythological woman whose hair was turned 

 into snakes), a jellyfish, or reproductive zooid of certain coelenterates. 



meroblastic, mer o bias 1 tik (Gr. meros, a part ; blastos, a germ), applied to 

 eggs only part of which are cut up into cells during cleavage. 



mesoderm, me' so derm (Gr. mesos, middle; derma, skin), the middle germ 

 layer of triploblastic animals. 



mesoglea, mesogle'a (Gr. mesos, middle ; gloia, glue), the gelatinous sub- 

 'stance between the ectoderm and entoderm of coelenterates. 



metabolism, metaVolizm (Gr. metabole, change), the processes connected 

 with the manufacture and destruction of protoplasm. 



