816 Appendix 



Anterior (an -te' ri or) (L. anterior ^ front), or head end. 



Anteroposterior differentiation, body with front (head) and hinder (tail) ends. 



Anther (an' ther) (Gr. anthos, flower), pollen-producing part of a plant stamen. 



Antheridia (an ther -id' i a), the male sexual organs that produce sperm in cer- 

 tain flowerless plants. 



Antheridiophore (an ther -id' i o for) (Gr. antheridia; phoreo, to bear, antheridia- 

 bearing structure. 



Anthocyanin (an tho cy' a nin) (Gr. anthos, flower; kyanos, blue), a coloring 

 matter of certain higher plants which impart a red or blue color. 



Anthozoa (an tho -zo' a) (Gr. anthos, flower; zoa, animals), flowerlike coelenterate 

 animals, including corals, sea anemone, etc. 



Anthropoid (an' thro poid) (Gr. anthropos, human), manlike organisms. 



Anthropology (an thro -pol' o ji) (Gr. anthropos, human; logos, science), the 

 science of ancient man and his development. 



Antibiotic (anti bi -ot' ik) (Gr. anti, against; bios, life), antagonism of one or- 

 ganism toward another; a drug, chiefly from bacteria and true fungi. 



Antibody (an' ti bod i) (Gr. anti, against; A.S. bodig, body), a substance en- 

 gendered in an organism by the presence of a foreign material, especially 

 bacterial proteins; an antibody is specifically antagonistic to the antigen 

 or substance under the influence of which it was formed. 



Antigen (an'tijen) (Gr. anti, against; gen, to form), a substance causing the 

 formation of an antibody. 



Antimere (an' ti mere) (Gr. anti, opposed; meios, part), one of the parts of a 

 radially symmetrical animal, as the ray of a starfish. 



Antitoxin (an ti -tok' sin) (Gr. anti, against; toxikon, poison), a specific defensive 

 substance in a body, either existing naturally or produced as a result of the 

 presence of a specific toxin which it tends to neutralize. 



Aorta (a -or' ta) (Gr. aorta, raise), main artery arising from the heart. 



Aortic arches, arteries arising from the ventral aorta and supplying the gill re- 

 gions of vertebrate animals. 



Apical (ap' i kel) (L. apex, summit), apex, tip, or summit. 



Apopyle (ap'opil) (Gr. ap, from; pyle, gate), an opening through which water 

 passes from the flagellated canals of sponges. 



Apospory (a -pos' po ri) (Gr. apo, away; sporos, spore), the formation of a 

 gametophyte plant directly from sporophyte tissue rather than from a spore. 



Appendix (ap-pen'dix) (L. ad, to; pendere, to hang), an outgrowth, such as the 

 vermiform appendix of man. 



Apterous (ap' ter us) (Gr. a, without; ptera, wings), wingless. 



Archegoniophore (ar ke -go' ni o for) (Gr. archegonos, first of a race; phoreo, to 

 bear), basal structure which bears the archegonium. 



Archegonium (ar ke -go' ni um) (Gr. archegonos, first of a race), female, multicel- 

 lular sex organs in plants. 



Archenteron (ar -ken' ter on), (Gr. archos, beginning; enter on, intestine), the 

 primitive digestive tract. 



Archeology (ar ke -ol' o ji) (Gr. archos, beginning; logos, science), a study of 

 ancient peoples from their relics, equipments, etc. 



Aristotle's lantern, the chewing apparatus of sea urchins. 



