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 examination 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 recognising 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 structure 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 connection 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. Crisp 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. Col. O'Hara's communication on some peculiarities of form and independent movement in blood-corpuscles, and a subsequent letter on the subject were read. Photo-micrographs in illustration were also exhibited. Dr. Maddox said that in Dr. Sternberg's "Photo-micrographs," a blood-corpuscle from a yellow-fever patient was figured which he thought showed the same kind of appearance as that described. Col. O'Hara also further explained the results of his examination. Mr. Crisp read a letter from Dr. Van Heurck on the advantage he had found in mounting in styrax, and exhibited the slides which he had sent. Mr. J. P. Bisset's "List of Desmidies, found in gatherings made in the neighbourhood of Lake Windermere during 1883," was taken as read. Mr. W. B. Turner's communication on Microthamnion vexator, a new species of fresh-water alga, was read, and a specimen exhibited. Mr. Crisp read a list of Fellows who had been nominated for election at the February Meeting as Officers and Council for the ensuing year. Mr. P. J. Butler and Mr. R. Kemp were duly elected Auditors of the Treasurer's accounts. The following Instruments, Objects, &c., were exhibited : Dr. Beale Slides illustrating his paper. : Mr. Crisp-Bulloch's Objective Attachment. Mr. J. Mayall, jun. :-(1) Parsons' Current Slide; (2) Nelson's Microscope Lamps. Col. O'Hara :-Photo-micrographs of Blood-corpuscles. Mr. W. B. Turner :-New Fresh-water Alga. Dr. Van Heurck :-Diatoms mounted in styrax. JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY. APRIL 1884. TRANSACTIONS OF THE SOCIETY. III.—Observations on the Life-History of Stephanoceros (Read 8th November 1882, and 12th March 1884.) PLATE V. FIGS. 1-3. In the course of some observations to verify the fact that the cell of Stephanoceros Eichhornii is tubular, I determined to try the experiment of freeing the creature from its cell. I accordingly took a fine and healthy individual from my tank, placed it on the plate of the live-box with a small quantity of water, and after carefully observing it with a 1/2 in. objective and C eye-piece, I made an incision in the cell, and severed the creature's tail just above the sucker. After paring down the leaf to which it was attached, and substituting a 2-in. objective, I took a very fine lancet, and steadying the leaf with a needle and watching my opportunity, I severed the muscles, cutting the tail through close to the base, and I had the gratification of seeing it swim out of the cell, leaving the cell perfectly intact. I subsequently again tried the experiment, with the following results (extracted from my diary). On Monday, May 15th (10 P.M.) I placed a good specimen of Stephanoceros Eichhornii in a moderately deep circular trough with a square base, my object for so doing in preference to using the live-box being to ascertain what amount of vitality existed after disconnection. This time, instead of merely making a small incision in the cell, I cut it straight across, completely dividing the cell, a small portion with the lower end of the tail being left attached to the piece of weed. The other, containing the animal and the greater portion of the cell, I dragged away into the middle of the trough, and awaited results. At first the creature did not attempt to move, its tentacles being completely closed up Ser. 2.-VOL. IV. N |