. Professor Tyndall on Germs. 347 
Figure 3. Conidia more highly magnified. 
Figure 4. Section through one side of a cavity containing stylospores. From 
mazzard cherry. 
Figure 5. Stylospores more highly magnified. 
Plate IV. Fignre 1. Section of choke-cherry stem, showing the mycelium before it 
has come to the surface, magnified six hundred diameters. 
Figure 2. Spermogonia. 
Figure 3. Asci and spores of Spheria morbosa from the choke-cherry. 
Figure 4. Perithecium with asci. 
1876.] 
Figures 5, 6. Ripe ascospores. 
Figures 7, 8. Ascospores germinating. 
2 PROFESSOR TYNDALL ON GERMS. 
NDER this head, Nature gives an abstract of a paper read 
. by Professor Tyndall before the Royal Society, January 
3 13th, entitled On the Optical Deportment of the Atmosphere 
: in Reference to the Phenomena of Putrefaction and Infection. 
: Among other things, he wished to free his mind, and if possible 
the minds of others, from the uncertainty and confusion which 
i now beset the doctrine of “spontaneous generation.” Pasteur 
has pronounced it “a chimera,” and expressed the undoubting 
conviction that, this being the case, it is possible to remove para- 
sitic diseases from the earth. We make a few extracts from this 
interesting article: — 
“ To the medical profession, therefore, and through them to 
: humanity at large, this question is one of the last importance. 
But the state of medical opinion regarding it is not satisfactory. 
In a recent number of the British Medical Journal, and in an- 
Swer to the question, ‘In what way is contagium generated and 
communicated ?’ Messrs. Braidwood and Vacher reply that not- 
; withstanding ‘an almost incalculable amount of patient labor, 
the actual results obtained, especially as regards the manner of 
generation of contagium, have been most disappointing. Ob- 
Servers are even yet at variance whether these minute particles, 
whose discovery we have just noticed, and other disease germs, 
ate always produced from like bodies previously existing, or 
whether they do not, under certain favorable conditions, spring 
Into existence de novo.’ . . . 
“ The result of the experiments showed that infusions of vari- 
ous substances exposed to the common air of the Royal Institu- 
tion laboratory, maintained at a temperature of from 60° to 70° 
Fahr., all fell’ into putrefaction in the course of from two to four 
