PROCEEDINGS OF THE SOCIETY. 167 



when they appeared in print, many of the particulars would be more 

 fully entered upon ; but with regard to the spiral vessels of plants 

 found in the mud, and the suggestion that they belonged to cabbage 

 which had passed through the intestinal canal of man, he believed 

 that it was a fact that they were without any work upon the anatomy 

 of the spiral vessels which was at all conclusive upon the subject, or 

 any information which would enable them to discriminate between 

 the spiral vessels of different plants, or between those from different 

 parts of the same plant. Before, therefore, it would be possible to 

 accept the evidence as conclusive, they required some controlled 

 experiments to prove that such things did not exist in water which 

 was free from all suspicion of sewage. The cabbage, as was well 

 known, belonged to an order of plants very common on the banks of 

 the Thames, watercress for example growing there in large quantities, 

 besides which cabbage was an article extremely likely to be thrown 

 overboard from vessels and barges, so that he should be very 

 careful in coming to a conclusion that these spiral vessels necessarily 

 had their origin in the sewage. 



Dr. Maddox said that some years ago he made a similar examina- 

 tion of water and mud from a field which had been irrigated with 

 sewage. He took some from the inlet, and the other from a place 

 just below the inlet, and he had not the slightest difficulty in recog- 

 nising specimens in Dr. Beale's drawings as being of the same kind 

 as those which he found on that occasion. Amongst other things, it 

 was quite easy to identify muscular fibre, some of which was very 

 imperfectly digested, also minute portions of broken shell, but the 

 chief thing which struck him was the great excess of muscular fibre 

 in proportion to the quantity of vegetable matter. There might have 

 been portions of coal, but he did not remember recognizing its struc- 

 ture so clearly as Dr. Beale had done, but it struck him as being a 

 dangerous process to irrigate fields with this kind of refuse, and then 

 to drink the water from streams into which such water drained. 



Dr Beale said he quite agreed with Mr. Bennett that it was 

 impossible actually to identify the spiral vessels, but having regard 

 to their identity with those obtained from cabbage, the chief point 

 upon which he laid stress was the very great quantity of them found, in 

 excess of all that could be well accounted for in any other way. Then 

 again, it was well known that the number of vegetables growing 

 upon the banks of the river went on decreasing, whilst the quantity 

 of mud kept increasing. There was one point of interest in connec- 

 tion with the subject which he ought to have mentioned, and that was 

 the marked difference in the death rate of London since the present 

 system of drainage was adopted. In 1870, when the system was first 

 set to work, the rate of mortality was 24 • 4, and it had since that 

 time decreased, until now it was only 21 •4, so there was every 

 encouragement for every one to do his best to get rid of the sewage, or 

 to dilute it still further. 



Mr. Crisj) referred to a paper by Mr. G. Acheson (Proc. Canad. 

 Inst. i. (1883) pp. 413-26), with fourteen pages of description of 

 organisms found in the tap water of Toronto. 



