8 ANNIVERSARY ADDRESS. 
presence of air had failed to accomplish. Nor is the effect here 4 
mentioned to be ascribed to a mere suspension of the life of the 
germs. They are deprived of life when they are deprived of air ; 
for when after a sufficient time germless air is restored to the 
infusions it fails to revive them. There is a singular similarity 
between the vital actions of these lowest organisms and those of 
the highest. \Privation of oxygen stifles both high and low, and 
excess of oxygen poisons both. Professor Tyndall concludes by 
saying that he is led inexorably tc the conclusion that no evi- 
dence of “spontaneous generation” exists, and that in the low- 
est as in the highest of organized creatures the method of nature 
is that life shall be the issue of antecedent life. A perusal of 
Professor Tyndall’s paper on the subject, contributed to the 
Nineteenth Century Review, in January last, will well repay any 
one who will take the trouble to look it up. Professor Sander- 
son, who at one time favoured the belief in the possibility of 
spontaneous generation, has since announced himself as entirely 
in accord with Professor Tyndall on the general question. 
Fhe important researches of Mr. Dallinger and Mr. Drysdale on 
the origin and development of minute and low forms of life, which 
were communicated by Mr. Dallinger to the Royal Institution in 
May last, being closely allied to the question of spontaneous | 
generation, call for passing notice. After years of special train- | 
ing for the work, these gentlemen watched in turns through a 
powerful microscope the whole life and reproduction of a monad. 
The largest specimens examined by them were the one-thou- 
sandth of an inch when young, and four-thousandths of an inch 
when adult. The spores were so small that it required a magni- 
fying power of 5,000 diameters to see them as they began to 
grow. Among other points of interest, they observed that while 
it was possible for monads to live with a gradual change of 
temperature from 45° to 125°, any sudden increase of heat was 
fatal ; and that, whilst adults could stand 140°, the spores could 
live for ten minutes in a temperature of 300°. : 
‘In December last, Professor Stokes ieated to the Royal 
Society some of the latest investigations of the radiometer, and set 
