GLOSSARY

NOTE TO THE STUDENT IN REGARD TO TECHNICAL TERMS

In the following glossary, which is added for the convenience of the student, I have given the derivation as well as the definition of many of the technical terms which are used in the text. A large part of our college population in these days is totally ignorant of Latin, and a larger part has never become acquainted with Greek. But even those who are not classical students may profit by cultivating the habit of looking up the etymology of words. One may easily acquire a stock of root words which give the clue to the meaning of a large number of technical terms. The common Greek and Latin prefixes and suffixes can be mastered in a very short time. Every college student is presumably going to be occupied with intellectual pursuits, to a greater or less extent, during the rest of his life, and he should therefore attempt to gain some insight into the make-up of the words he frequently encounters. He should at least learn the Greek alphabet in order to make the best use of an English dictionary.

Aboral (Lat. ab, from; os, mouth), opposite the mouth.

Afferent (Lat. ad, to; ferre, to carry), a term applied to nerves carrying impulses toward a center.

Albumin (Lat. albumen, white of egg), a protein occurring in the white of eggs.

Alveoli (Lat. alveolus, a small cavity), small cavities or spaces resembling cells.

Amino acid, an acid containing the amino group NH2.

Amitotic (Gr. a, without; uiros, thread), without mitosis, a term ap

plied to cell division.

Amoeboid (Gr. åμoɩßý, change), like an Amœba.

Amphibia (Gr. ȧupi, both; Bíos, life), a class of vertebrates including frogs, newts, and related forms.

Anabolism (Gr. ȧvaßoλń, that which is thrown up), constructive metabolism.

Anaërobic (Gr. ȧv, not; anp, air; Bios, life), capable of living without

free oxygen.

Antheridium (Gr. åveŋpós, flower), an organ producing male sex cells in ferns and other flowerless plants.

Anthropoid (Gr. åveрwños, man), manlike. Applied to the higher apes. Antitoxin (Gr. ȧvri, against; Tоğıxóv, poison), a substance which neutralizes a poison.

Arachnida (Gr. ȧpáxvn, spider), a group of arthropods including spiders, scorpions, mites, etc.

Archegonium (Gr. ȧpxń, beginning; yóvos, fruit), an organ bearing female sex cells in ferns and other flowerless plants.

Artery (Gr. åρTepia, artery), a vessel carrying blood from the heart. Arthropod (äp@pov, joint; πoús, foot), a phylum of invertebrate animals with segmented bodies and jointed appendages.

Aster (Gr. ȧorp, star), a starlike body appearing during mitotic cell division.

Atavism (Lat. atavus, ancestor), a reversion to an ancestral type.

Bast, the phloëm part of fibrovascular tissue.

Biology (Gr. Bios, life; Xóyos, discourse), the science of life.

Blastopore (Gr. ßλaσrós, germ; πóρos, passage), the mouth of the gastrula.

Blastula (diminutive of Bλaorós, germ), an embryonic stage consisting of a hollow sphere of cells.

Brachiopods (Gr. ẞpaxiwv, arm; Tous, foot), a group of invertebrates with bivalved shells resembling those of bivalved molluscs, but belonging to a very different group.

Calyx (Gr. xáλuğ, a cup), the outer whorl of floral organs.

Cambium (Lat. cambio, exchange), the growing layer between wood and bark.

Cambrian, the first division of the Paleozoic era; named from Wales (Lat. Cumbria).

Carboniferous (Lat. carbo, coal; ferre, to bear), a prominent coalbearing period of the Paleozoic era.

Carnivora (Lat. caro, flesh; vorare, devour), a flesh-eating order of mammals, including cats, wolves, and their allies.

Castration (Lat. castrare, to castrate), the removal of the sex organs. Catalysis (Gr. xaráλvous, dissolution), the acceleration of a chemical transformation by a substance which is not destroyed in the process. Cellulose, the carbohydrate forming the cell wall of plants. Centrosome (Gr. xévтpov, center; oua, body), a small body occurring at the poles of the spindle in mitotic cell division. Cephalopoda (Gr. xeyaλý, head; Toús, foot), a group of molluscs including the squid, octopus, nautilus, and many extinct relatives. Cercaria (Gr. xéрxos, tail), the tailed larva of a fluke.

Cestode (Gr. xeσтós, a girdle), a tapeworm.

Chlorophyll (Gr. xλwpós, green; púλλov, leaf), the green coloring matter of plants.

Chordata (Gr. Xopon, cord), a phylum of animals having a notochord. Chromatin (Gr. xp@ua, color), a deeply staining substance of the nucleus.

Chromosomes (Gr. Xpŵua, color; oua, body), a (usually) thread-
like body of chromatin appearing in mitotic cell division.
Cilia (Lat. cilium, eyelash), hairlike processes of cells.
Cœlenterate (Gr. xoîλov, cavity; evrepov, gut), a member of a

phylum of invertebrates including hydroids, jellyfish, corals, etc. Cœlom (Gr. xoîλov, cavity), the space between the intestine and body wall in the Cœlomata.

Colloids (Gr. xóλλa, glue), substances with aggregated molecules which do not ordinarily diffuse through membranes.

Corolla (Lat., little wreath), the usually colored whorl of floral organs next above the calyx.

Cranium (Gr. xpaviov, skull), the brain case.

Cretaceous (Lat. creta, chalk), a subdivision of the Mesozoic era represented in some localities by chalky deposits.

Crustacea (Lat. crusta, crust), a group of arthropods including crabs, crayfish, shrimps, and their allies.

Cyst (Gr. xúσrn, sac), a protective envelope surrounding an organism

in a resting stage.

Cytology (Gr. xúтos, cell), the study of cells.

Cytoplasm (Gr. xúтos, cell; πλáoμa, formative material), the protoplasm of a cell outside the nucleus.

Dendrite (Gr. dévôpov, tree), a branching process of a nerve cell.
Devonian, a period of the Paleozoic named from Devonshire.

Dextrose (Lat. dexter, right), a sugar commonly found in fruits.

Diatom (Gr. dís, double; aтoμos, indivisible), a unicellular plant with a bivalved siliceous shell.

Dimorphism (Gr. dis, double; μopon, form), having two forms.
Dorsal (Lat. dorsum, back), pertaining to the back.

Echinoderm (Gr. èxîvos, hedgehog; dépμa, skin), a phylum of inver

tebrates including starfishes, sea urchins, crinoids, and their allies. Ectoderm (Gr. Exтós, outside; dépμa, skin), the outer germ layer of the embryo.

Ectoplasm (Gr. ¿xrós, outside; πλáσμa, formative material), the outer part of the protoplasm of cells.

Edentates (Lat. ex, out; dens, tooth), an order of mammals including

the sloth, armadillo, anteater, and more numerous extinct species. Efferent (Lat. ex, out; ferre, to carry), a term applied to nerves which carry impulses away from a center.

Endocrine (Gr. evdov, within; xpivw, I separate), pertaining to organs of internal secretion.

Endoderm (Gr. évdov, within; dépμa, skin), the inner germ layer of the embryo.

Endomixis (Gr. evdov, within; μîtes, mingling), nuclear reorganization without conjugation.

Endoplasm (Gr. ěvdov, within; Tλáoμa, formative material), the inner part of the protoplasm of cells.

Enzyme (Gr. ¿v, in; Šúμŋ, a ferment), a ferment.

Eocene (nús, dawn; xaɩvós, recent), the earliest period of the Tertiary.

Epidermis (Gr. ẻπí, upon; dépμa, skin), the outer layer of the skin. Epigenesis (Gr. éπí, upon; yéveσɩs, origin), the doctrine that devel

opment proceeds from a simple, unorganized germinal substance. Eugenics (Gr. eû, good; yéveσɩs, origin), a study of the agencies that affect the quality of the human breed.

Eustachian tube (Eustachius, an Italian anatomist), the passage from the middle ear to the pharynx.

Fauna (Lat. Faunus, god of shepherds), the animal life of a region. Femur (Lat. femur, thigh), the thigh bone.

Fission (Lat. fissio, cleavage), the division of a cell or organism into two or more parts.

Flagellum (Lat. flagellum, a little whip), a lashlike process of a cell. Flora (Lat. flos, flower), the plant life of a region.

Frond (Lat. frons, leaf), a leaflike expansion of one of the lower plants.

Gamete (Gr. yaμérns, spouse), a sex cell.

Gametophyte (Gr. yaμérns, spouse; vτóv, plant), a plant bearing sex cells; the sexual generation.

Ganglion (Gr. yayyλcov, swelling), a group of nerve cells.

Gastrula (Gr. yaσrnp, belly), the two-layered stage of the embryo. Gene (Gr. yéveσɩs, origin), a hereditary factor.

Genetics (Gr. yéveσɩs, origin), the science dealing with heredity and variation.

Germ layer, one of the fundamental layers of the embryo; ectoderm, entoderm, mesoderm.

Gland (Lat. glans, nut), an organ of secretion.

Glycogen (Gr. yλuxus, sweet; yéveous, origin), a form of carbohydrate (animal starch) found in the liver and other parts.

Gonad (Gr. yóvos, reproduction), an organ producing sex cells.

Hæmoglobin (Gr. aîμa, blood; Lat., globus, globe), the red oxygencarrying protein of the red corpuscles.

Hepatic (Gr. 'nπap, liver), relating to the liver.

Hermaphrodite (Gr. 'Epuns, Hermes; 'A❤podiтn, Aphrodite), an organism with both sexes combined.

Heterozygous (repos, different; (vywrós, joined), an organism with different genes for a given character.

Histology (Gr. ioros, web; λóyos, discourse), the science of tissues. Holophytic (Gr. öλov, altogether; quтóv, plant), typically plantlike in nutrition.

Holozoic (Gr. öλov, altogether; (@ov, animal), animal-like in nutrition. Homology (Gr. duoλoyía, agreement), structural similarity due to descent.

Homozygous (Gr. öuos, like; (vywrós, linked), having like factors for a given character.

Hormone (Gr. öpμwv, that which sets in motion) an internal secretion.

Intussusception (Lat. intus, within; suscipere, to take up), the addition of material throughout the mass.

Invertebrate (Lat. in, not; vertebra, backbone), an animal without a backbone.