GLOSSARY. 



cell (germ) grows. It divides into two, then each of the new 

 parts divides again into two, and so on. 



Somite (Gk. aSitw,, body). — A term applied to the successive parts, 

 segments, or metameres, of a segmented animal, because each 

 of these parts usually bears appendages, and thus affords a 

 distinction of body and limb. 



Spore Formation. — Sometimes the nucleus and protoplasm of 

 a cell, instead of dividing into two in the ordinary way, divide 

 into several parts lying in the middle of the cell, so that the out- 

 side layer of the old cell is left unchanged, until it is destroyed 

 by the activity of the new cells, which burst it and make their 

 way out. This is called "spore formation," or "endogenous 

 cell-formation." It occurs in the reproduction of some of the 

 Protozoa (pp. 129, 136, 140). 



Syncytium (Gk. aiv, together, and kutos, a hollow vessel, i.e. cell). 

 — A colony of cells intimately united with one another by 

 means of amoebitorm processes. This has been shown to be the 

 case with the cells which form the " segments " of the develop- 

 ing egg-cell. 



Tissue (French, from Lat. textus. woven, a thing woven). — The web 

 or substance of animal bodies, made up, not of threads, but of 

 cells (plastids). 

 Unicellular. — Consisting of one cell {vlastid). This is not the case 

 in the adult stage with animals not belonging to the Protozoa; 

 but each animal starts at first from one cell only, by the division 

 of which the body is gradually formed. 

 Viviparous (Lat. viviis, alive, andpaiio, to bring forth). — Produc- 

 ing live young, The majority of animals produce their young 

 from eggs ; the Mammalia are the only animals that are vivi- 

 parous as a group, and by the necessity of their structure. 

 Occasional species among many groups of animals bring forth 

 their young alive ; but in these exceptional cases there is little 

 special adaptation of structure for the purpose. They may be 

 looked upon as cases in which the eggs or larvaj are delayed 

 within the body of the parent until ready for independent exis- 

 tence, and are described by the term ovo-viviparous. 

 Zoology (Gk. fJSoi', animal, and Xoyos). — The study of animal life, 

 especially its study from the point of view ol systematic 

 classification. 



