215 
estimates that 10,000 eggs must have escaped daily for 
many months. He concludes, from experiments as to the 
effects of reagents on the living embryos, that there is not 
likely to he any risk of its spread by means of sewage 
distribution, as they were killed by water in which decom- 
posing matter of any land had been introduced, and indeed 
required water almost absolutely pure for their development. 
The addition of a little salt to the water seemed, however, 
to act favourably. The conditions apparently required in 
these experiments are veiy unlikely to be met with in 
nature, and if they were necessary, the worm should, I 
think, have been extinct long ago in its native home. 
With the exception of temperature, the other conditions 
for their development are probably present with us, and we 
do not as yet know that the former is essential. The truth 
seems to be that the circumstances necessary for their 
development are still unknown, and that it is premature to 
assume that sewage distribution will not increase the risk 
of its becoming acclimatized among us. 
Specimens of nearly all the descriptions of Caoutchouc 
known to Commerce were exhibited by Mr. Spencer H. 
Bickham, and a paper was read illustrative of the probable 
sources of supply, and the chief characteristics of each class. 
The following report of the Council and Treasurer’s 
Account for the past year were read and passed : — 
Your Council have to report that during the past Session 
papers on the following subjects have been read at the 
meetings : — 
1870. 
Oct . 10. — “On Abraxas grossulariata,” by Joseph Sidebotham, 
F.R.A.S. 
JS T 0V _ 7. — “ The Hawthorns of the Manchester Flora,” by Charles 
Bailey. 
