235 
by the Agency of Insects . 
fungi in relation to the transport of bacteria. The teleology of 
the bad odours of putrefaction has, so far as I am aware, never 
been explained ; but since these odours depend upon the pre- 
sence of organisms, and serve to attract multitudes of flies, 
and since it is a rule in Nature that no organism aids another 
except, so to speak, with the object of ultimately benefitting 
itself, it seems to me highly probable that the odour of putre- 
scent matter has been developed in relation to the visits of 
flies. The advantage to the bacteria is obvious, for by the 
odour produced, the irregular fortuitous action of the wind is 
largely replaced by the direct purposive action of insects ; and 
hence, once the odour is developed, flies will form the chief 
means of dispersal. It has been shown above that spores may 
retain their vitality during their passage through the digestive 
canal of flies, and there can be little doubt the same applies to 
bacteria. Flies may thus serve to disperse not only the micro- 
organisms associated with putrefaction, but also those which 
are the cause of certain diseases, such as anthrax, etc., in 
which the products are attractive to them ; and since flies, 
apart from their own powers of locomotion, are known to be 
carried long journeys in railway trains and steamers, they 
may serve to carry infection and spread diseases to distant 
places. 
BIBLIOGRAPHY IN CONNECTION WITH 
TABLE II. 
1. Micheli, Nova Plantarum Genera, p. 202, Tab. LXXXIII, 1729; Berkeley, 
Outlines Brit. Fungi, p. 297, PI. XX, Fig. 3, i860 ; Cooke’s Brit. Fungi, vol. i. 
p. 364. 1871. 
2. Curtis, Brit. Entom., vol. x, Tab. 469, 1833 ; Berk., Outlines Brit. Fungi* 
p. 298. i860. 
3. Corda, Icon. Fung., tom. vi, p. 19, Taf. Ill, Fig. 46. 
4. Hooker’s Journ. Bot., vol. iv, p. 69, 1845; Corda, Icon. Fung., tom. vi, 
p. 19, Taf. Ill, Fig. 47. 
i 
