302 MICROBES AND TOXINS 



Gametes — sexually differentiated cells which unite to form the 

 fertilized cell, the zygote. 



Glucosides — substances which are capable of decomposition into a 

 sugar (glucose), and various other organic substances, alcohol, 

 phenol, aldehyde, &c. For example, amygdalin the active 

 principle of bitter almonds breaks up into glucose benzaldehyde 

 (the odorous constituent) and hydrocyanic (prussic) acid. 

 Many poisonous plants contain glucosides as their active 

 principle. 



Glycogen — a carbohydrate analogous to the starches, stored by the 

 body in the cells of the liver and muscles, and drawn upon by 

 the body for the supply of sugar consumed by the cells during 

 muscular work and other activities. 



Humours — body^uids, for example the aqueous and vitreous 

 humours of the eyeball. 



Incubation — the time elapsing between the moment of penetration 

 of the body by a virus (microbe or toxin) and the moment when 

 the first symptoms appear. 



Indol — Among the products of the digestion and putrefaction of 

 proteins (q.v.) there appears a substance, tryptophane, from 

 which the indol bodies are derived, indol and skalol (indicated 

 by various colour reactions depending upon their relationship 

 to indigo) : also a substance, tyrosin, from which are derived 

 paracresol omA phenol (carbolic acid). 



Inflammation — the reaction of living tissues to injuries and 

 infections. The essential fact in inflammation is the activity 

 of cells, the phagocytes which are capable of taking up 

 substances and digesting them. 



Isomeric — with different chemical or physical properties but 

 containing the same quantity of chemical elements in the 

 molecule : the difference is due to the different arrangement in 

 space of the atoms in the molecule. 



Lipoids — a group of substances such as lecithin, cerebrin, protagon 

 cholesterin, possessing certain of the properties of fats (Xotov — 

 fat). The name was introduced by Overton to indicate the 

 possession by these bodies of powers of solution similar to fats, 

 in particular for anasthetics. According to Overton the outer- 

 most layer of protoplasm in a cell consists of lipoid substances 

 and the cell alosorbs only those materials which are soluble in 

 the lipoids. 



Medulla — the medulla oblongata or bulb is the continuation of the 

 spinal cord within the skull before its junction with the brain : 

 it contains the nuclei of certain cranial nerves regulating the 

 respiration and the heart-beat. 



Molluscum contagiosum — an infectious skin disease characterized 

 by small teat-like protuberances. 



MucedineEE — fungi of the group to which the ordinary white mould 

 mucor mucedo belongs. 



