388 



Glossary 



protoplasmic mass containing 

 many nuclei, but not set off into 

 distinct cells. The entire em- 

 bryo is of this character in some 

 animals. In fact a few embry- 

 ologists have contended that dur- 

 ing the embryonal stages of 

 most, if not all animals, the cells 

 are connected by protoplasmic 

 strands and bridges, making 

 them syncytia. The undoubted 

 wide prevalence of syncytial 

 structure among animals espe- 

 cially, has been used as an argu- 

 ment against the cell-theory. 

 Synthesis. From the organismal 

 standpoint not many terms used 

 in biology are more important 

 than this. The etymological 

 meaning, placed or put together, 

 expresses onh^ a part of the to- 

 getherness of an organism; the 

 part, namely, which pertains to 

 the assimilative activity per- 

 formed by the organism on its 

 nutritive substances. This proc- 

 ess may be regarded as a syn- 

 thesizing one in nearly the lit- 

 eral sense (though even here the 

 process is more one of self-ac- 

 tivity and less one of external 

 agency than seems to be implied 

 in the original word). But it is 

 when we come to consider the 

 original nature and power of the 

 organism by virtue of which it 

 assimilates food, that the inad- 

 equacy of synthesis, except in a 

 much modified sense, comes to 

 light, for the organism's ability 

 to assimilate, that is to put or 

 place together, its nutritive sub- 

 stances is wholly dependent, so 

 far as we have evidence, on the 

 fact of its being already and 

 originally a together entity. An 

 organism is able to put together, 

 or synthesize, its food just be- 

 cause it itself is together, or syn- 

 thesized. A synthesized state is 

 a prior condition to synthesizing. 

 To be an organism at all is to be 



synthesized. 



Systematic. Pertaining to a sys- 

 tem; literally a standing or being 

 together. It is unfortunate that 

 "systematic" has come to be re- 

 stricted in its application in re- 

 cent biology to the formal classi- 

 fication of plant and animal 

 species. As a matter of fact a 

 necessary consequence of the 

 unity of all phenomena of the 

 living world is that all these 

 phenomena "stand" in some nat- 

 ural and ascertainable relation 

 with all other phenomena, so 

 that all biological knowledge 

 whatever must of necessity be 

 systematic if it really corre- 

 sponds to nature. 



Taxonomy. Mode of arrangement, 

 the branch of biology which 

 deals with the classification of 

 the species of plants and ani- 

 mals. 



Test. As used in zoology and bot- 

 any, an external covering or 

 tunic, usually nearly lifeless, 

 tough and resistant. Its office is 

 mostly protective. 



Thymus. A gland of internal se- 

 cretion found in the neck region 

 in all vertebrates, and connected 

 originally with the gill system. 



Thyroid. One of the most impor- 

 tant glands of internal secretion, 

 located, as is the thymus, in the 

 neck region, but connected em- 

 bryonically with the pharynx 

 rather than with the gills proper. 



Trochophore. a larval stage in 

 the lives of many marine worms 

 and molluscs, characterized by 

 being well organized for swim- 

 ming by means of cilia variously 

 disposed on the surface of the 

 body. 



Trypsin. One of the chief "active 

 principles," or enzymes of pan- 

 creatic juice. It splits proteids 

 into simpler compounds. It is 

 produced by some plants as well 

 as many other animals than man 



