384 PRINCIPLES OF ANIMAL BIOLOGY 



Grew, Nehemiah. English botanist, 1641-1712. 



Gullet. A tube leading from the posterior end of the oral groove in Paramecium to 

 the interior of the cell. 



Habitat. The kind of place in which an organism lives. 



Halogen. One of a family of chemical elements including chlorine, iodine, bromine, 



and fluorine. 

 Halysites {hal' i si' teez). A genus of extinct chain corals. 

 Haploid. Single; referring to the reduced number of chromosomes in the mature 



germ cells of bisexual animals. Cf. diploid. 

 Harvey, William. English physician and physiologist, 1578-1657. 

 Hemoglobin. A reddish protein contained in the red blood cells. 

 Heparin {hep' a rin). A substance extracted from liver, carbohydrate in nature with 



amino and phosphate components, used to prevent clotting of blood. 

 Hepatic portal system. The portal system leading from the stomach, intestine, 



pancreas, and spleen to the liver. 

 Herbivorous. Plant-eating. 

 Heredity. The occurrence, in organisms, of any qualities due to the nature of the 



protoplasm of which they are made. 

 Hermaphrodite. An organism possessing both male and female organs. Also 



(adjective), possessing the organs of both sexes. 

 Herpetology [her pe toV oji). The zoology of reptiles and Amphibia. 

 Heteromita lens. A species of flagellate protozoon. 



Heteromorphes {het' er o mor' Jeez). A group of animals in Blainville's early classifi- 

 cation; animals of irregular form, mainly sponges and Protozoa. 

 Heterozygote. An organism to which its two parents have contributed unlike genes 



with respect to some inherited character, and which in turn produces two kinds 



of germ cells with respect to that character. 

 Heterozygous. Of the nature of a heterozygote. 

 Hexactinellida {heks ak ti neV It da). A class of Porifera (sponges) whose spicules 



are composed of silica. 

 Hipparion {hip pa' ri on). An extinct horselike animal of ^Miocene and Pliocene 



time in North America and Europe. 

 Hippocampus {hip' po kam' pus). A genus of fishes of bizarre form resembling in 



part tlie head of a horse. 

 Hippocrates {hip pok' ra teez). Greek physician. Father of Medicine, 460-359 (?) B.r. 

 Hirudinea {hi' ru din' e a). A class of Annelida comprising the leeches. For defini- 

 tion see ( 'hap. 19. 

 Holothurioidea {ho' lo thu' ri oi' de a). A class of Echinodermata, comprising the 



sea cucumbers. For definition see Chap. 19. 

 Homo. The genus of animals comprising man. 

 Homolecithal ihn' mo Ics' i thai). Having little yolk, nearly evenly distributed; said 



of ("figs. 



Homologous iho inol' o giis). Originating in the same wa\' in evolution; said of organs 



or structures. 

 Homology. Siniilaiit y of origin in evolution; api)lied to organs that arise in the 



same way. 

 Homozygote. An organism whose two parents contributed to it similar genes for 



some inherited character, and whose germ cells are therefore all alike with respect 



to that character. 

 Homozygous {ho' ino zi' gi(s). Of the Jialure of a homozygote. 

 Hooke, Robert. English natural philosopher and mathematician, 1635-1703. 



