NOTES AND MEMORANDA. 
373 
The Causes of Buzzing in Insects . — The number of ‘ Comptes 
Eendus ’ for 7tli October last* contains a note by M. Jousset de 
Bellesme on M. Perez’s paper on this subject wbicb aj)peared in an 
earlier number, and wbicb is translated at p. 276. The note is in 
substance identical with that wbicb is quoted from the ‘ Times ’ at 
p. 278, and as, altbougb somewhat more precise, it includes no addi- 
tional facts, it is unnecessary to reproduce it here. A translation 
aj^pears in ‘ Annals and Mag. of Nat. Hist.’ for November. 
The Germ Hypothesis of Putrefaction. — Dr. B. W. Richardson, F.R.S., 
delivered during the present year at the Society of Arts a series of six 
(Cantor) Lectures on “Putrefactive Changes and on the Preservation 
of Animal Substances.” The lectures concluded with a reference to 
the Germ Hypotliesis, of wbicb the following is an abstract : — 
This has been very differently treated by different authors. On 
one side it has been subjected to derision, on the other extolled to 
childish adulation. It may be said to have started with the observation 
of Redi, that the exclusion of dead animal matter from something in 
the air, which could apparently be filtered out of the air, arrests putre- 
factive change as it might arrest the introduction of the ova or germs 
of other living forms in the same substance. We have seen in our 
experiments that exclusion of air does, for a time, under some circum- 
stances, interfere with commencing putrefaction. 
This looks like truthful demonstration. Yet still it is a very easy 
thing to oppose the hypothesis altogether. We can show, that animal 
tissue decomposes in the closest chamber ; when imbedded in hard 
paraffin ; when coal-gas or other negative gas takes the place of air. 
All these facts indicate that air is not wanted either to act itself, or to 
convey particles or germs. 
But it may be urged on the side of the hypothesis, that the dead 
animal substances, before the time when they were subjected to these 
exclusive tests, had been exposed to the infection of germs. 
To this there is an experimental answer. Here are specimens 
which after having been subjected to the air itself, under pressure, had 
not decomposed ; and others which have been exposed to the air, but 
because they are charged with a small j:>art of a salt, or gas, or vapour, 
have not decomposed. Thus a substance may be exposed to the air 
and may not change. All our salted provisions may be used as argu- 
ments in siq^port of this truth. 
There will again be a ready answer to suit the hypothesis, namely, 
that under such conditions germs cannot live. The conditions are 
fatal to life in any form. How can germs live in cyanogen, or 
sulphurous acid, or under atmospheric pressure, beyond what is 
natural ? 
The answers are plausible, and the germ hypothesis might be de- 
fended possibly on them if there was nothing else to be said. But 
there is more behind. We can arrest life in action and still have 
decomposition. If I w'ere to put a firm ligature round one of my 
limbs, and so completely cut off the supply of blood, I should do the 
* Vok Ixxxvii. p. 535. 
