GLOSSARY* 



Abdomen (ab do'men), the portion of the trunk posterior to the thorax of an 

 animal. 



Aboral (ab 6'ral), opposite the mouth. 



Absorption (ab sorp shun), the process of taking in soluble foods by the circu- 

 latory medium or by the protoplasm directly. 



Accommodation (a kom 6 da'shun), the power of adjustment of the eye to near 

 and far objects. 



Acetabulum (as e tab'ti lum), the socket in each side of the innominate bone 

 of the pelvic girdle into which the femur fits. 



Achromatic figure (ak ro mat'ik), the mitotic figure without chromosomes. 



Aestivation (es ti va'shiin), state of torpidity induced by heat and dryness. 



Allelomorphs (a le'16 morfs), a pair oi corresponding genes in homologous 

 chromosomes, but each produces a different character. 



Allergy (al'er ji), acute sensitiveness to a foreign substance, as foreign protein 

 in the body. 



Alternation of generation (al ter na'shun of jen er a'shun). (See Metagenesis.) 



Altricial (al trish'al), in reference to birds which are hatched without feathers 

 and in a helpless condition. 



Alveolus (al ve'6 ICis), a small cavity or pit, such as the air sacs in the lung 

 of a higher vertebrate. 



Ambulacral (am bu la'kral), area of echinoderm related to tube feet. 



Amino acids (am'i no), organic acids with a (NHj) radical, and derived from 

 complex proteins. 



Amitosis (amito'sis), direct cell division, occurring without chromosomal ac- 

 tivity. 



Amnion (am'ni on), inner embryonic membrane of terrestrial vertebrates. 



Amoeboid movement (a me'boid), the streaming of protoplasm in a cell to ex- 

 tend the cell in some direction with the formation of pseudopodia. 



Amphiaster (am'fi as ter), the complete mitotic, figure of a dividing cell. 



Amphiblastula (am fi blas'tu la), the free-swimming larval form in sponges. 



AmpMmixus (am fi mik'sis), union of nuclear material from two different 

 cells, as in fertilization. 



Ampulla (am pul'a), a bulblike dilatation. 



Amylopsin (am i lop'sin), a pancreatic enzyme capable of converting starch 

 into sugar. 



Anabolism (an ab'6 liz'm), the building up of living protoplasm. 



Analogous (a nal'o gus), differing in structure and origin, but similar in func- 

 tion. 



Anaphylaxis (an a fi lak'sis), acute reaction of the body to foreign protein 

 materials which have a toxic effect; this may be an increased sensitivity 

 to the material because of previous contact with it. 



Anatomy (a nat'6 mi), the science that treats of the structure of organic bodies. 



Anus (a'nus), the posterior opening of the alimentary canal. 



Appendicular skeleton (ap en dik'u lar), skeleton of the paired fins of Pisces. 



Archenteron (ar ken'ter on), the cavity of the gastrula which is the primitive 

 digestive cavity. 



Artery (arteri), the larger blood vessels leading away from the heart. 



Asexual reproduction (a sek'shu al), reproduction without sex cells. 



Assimilation (as sim i la'shun), the transforming of digested food into proto- 

 plasm. 



Asymmetry (a sim'et ri), a condition in which the two sides of an animal are 

 dissimilar. 



•Phonetics according to Webster's New International Dictionary. 



510 



