226 GLOSSARY 



Saprophyte An organism capable of living on dead or 

 decaying matter. Adj., saprophytic. 



Serum (pi., Sera) The clear light yellow fluid part of the 

 blood which exudes after clotting has occurred, and in which 

 antibodies reside. 



Sexual Requiring two different forms for reproduction. 



Species The lowest biological division of living forms, 

 varying only in unimportant characters, but possessing all 

 the characters of the genus to which they belong. Lions 

 and tigers belong to the genus Felis (or cat family), but the 

 former belongs to the species "leo," and the latter to the 

 species " tigris. ' ' See Genus. 



Spirochseta (pi., Spirochaetae) The spiral or corkscrew-like 

 organisms; name given both to family and genus. 



Staphylococcus The spherical coccus which grows in 

 grape-like masses. 



Sterile Bacteriologically speaking, entirely free of living 

 organisms. A surgically sterile thing may contain organisms 

 from the air which do not hurt the patient. Related words: 

 sterility, sterilization, to sterilize. 



Strain An individual culture of a species isolated from a 

 case. 



Streptococcus The spherical coccus which grows in chains. 



Toxins The poisonous products of bacterial life. 

 Tumefaction Any tumor-like swelling. 



Vaccine Originally used for the inoculation of cowpox 

 as a protective against smallpox; now used for that and 

 for the injection of dead or attenuated bacteria for active 

 immunization or treatment during disease. See Bacterins. 

 Related words: to vaccinate, vaccination. 



Viable Capable of living and reproducing. 



Virulence The power possessed by organisms to develop 

 .poisons and produce disease. It varies in different strains, 

 but depends also upon the resistance of the host. 



Virus Any factor which produces disease, either individ- 

 ually recognized or obscure; usually applied to poisons not 

 specifically isolated, like rabies virus. 



