NOTES BY THE EDITOR. XI 



detailed account of the results of these investigations will be 

 found in subsequent pages." 



Professor Huxley, in his address at Liverpool, contributed some 

 new terms to science. 



The hypothesis that living matter always arises by the agency 

 of pre-existing living matter, he terms biogenesis ; and the doc- 

 trine that living matter may be produced by not-living matter, 

 abiogenesis. 



It may be well also to notice two other terms greatly used in 

 this branch of science : homogenesis and heterogenesis, or xeno- 

 genesis. When the living parent gives rise to offspring which 

 pass through the same cycle of changes as itself, like giving rise 

 to like, this is termed homogenesis ; when the living parent gives 

 rise to offspring which pass through a totally different series of 

 states from those exhibited by the parent, and do not return into 

 the cycle of the parent, this is termed heterogenesis or xeuo- 

 genesis ; like not giving rise to like. 



A late writer in " The Lancet " says : " The determination of 

 the nature and mode of existence of the contagious principles of 

 zymotic diseases has hitherto baffled the keenest search of scien- 

 tific workers ; but the employment of improved methods of observa- 

 tion is at length beginning to remove much of the mystery which 

 envelops the subject of contagion. Until we have unravelled the 

 nature of zymotic poisons, it is impossible to make any real prog- 

 ress in the discovery of efficient means of averting the spread of 

 epidemic and contagious diseases. From the^ results of a special 

 investigation, conducted for the Privy Council in England by Dr. 

 Sanderson, we are led to the conclusion that every kind of con- 

 tagion, as regards its physical form, consists of extremely minute, 

 separate, solid particles, to which the name microzymes is given ; 

 these particles being spheroidal, transparent, of gelatinous consist- 

 ency, of density equal to that of the animal fluid in which they are 

 contained, and, therefore, not deposited by subsidence, and com- 

 posed of albuminous matter. They are organized beings, self- 

 multiplying organic forms. The results of M. Chauveau's exper- 

 iments with small-pox, sheep-pox, and farcy poisons, all tell in 

 the same direction. It is apparent that the tendency of recent re- 

 searches is to induce a reaction in favor of the fungus origin of 

 zymotic disease." 



"The controversy about Spontaneous Generation, or Abiogen- 

 esis," remarks the "Lancet," "resembles history, it continu- 

 ally repeats itself. Notwithstanding the discussions at the meet- 



