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I
The cultivation of the different flagellates enumerated has afforded me the opportunity of making certain general observations bearing upon the question of their effects, if any, upon the bacterial population in the surrounding niedium. discuss these, since they may be of assistance to those engaged in the study of the important correlated subject of the effects of soil-protozoa upon the soil-bacteria. For it is not at all unlikely, especially in the case of soils well manured with dung. that the fauna in these, so far as regards the Amoeba and flagellates, is similar in I come to the con- character to the coprozoic fauna with which I have worked. olusion that the flagellates (and Amæbæ) are probably not the chief factor inhibiting bacterial development in the soil. I am more inclined to consider that the "limiting factor" is one which operates, equally or unequally, upon both the bacteria and the protozoa, and may perhaps be in some way connected with an excessive development of toxic products, or certain abnormal conditions, in the immediate environment. find nyself, therefore, more in agreement with Goodey than with Russell.
1
The second part of my memoir is a discussion upon the meaning or significance So far as we know now, the of the kinetonucleus in the binucleate flagellata. binucleate flagellates, including the non-parasitic genus Bodo, do not undergo syngamy. On the other hand, many, certainly-probably most or all of the related lowly protomastigine flagellates occurring in dung or infusions, which, of course, possess no kinetonucleus, do conjugate. I suggest, therefore, that there is a close connexion between these two developments, namely, the presence of the binucleate condition and the loss of syngamy. After a necessary reference to the question of what is the significance of conjugation in the first place, the following provisional conclusion is reached. In Bodo and the other biflagellate binucleates a development took place by which a certain nuclear constituent was removed from the immediate sphere of the nucleus and came to occupy an independent position in the cell; this permanent change in the molecular arrangement of the nuclear material facilitated the maintenance of the nuclear (or nucleo-cytoplasmic) stability, so that the cell became able to dispense with the necessity for periodic reorganization or rearrange- ment of its nuclear material by the process of syngamy, which was consequently lost. On the other hand, in the uniflagellate binucleates, of which all so far known are parasitic forms, the special environmental conditions reacted so favourably on the general metabolism that here, too, the cell-balance could be maintained "without recourse to conjugation, which at last no longer occurred (cf. our account of the non-conjugating strain of Helkesimastix, where this view has been more fully elaborated, vide last Report, Cd. 7796). But, as a sequel, a double-nuclear condition was also developed, perhaps in order to facilitate the more equal division of the trophic and kinetic nuclear elements. My attempt is the first, I believe, which has been put forward to give a logieal raison d'être for the characteristic binucleate con- dition of the trypanosomes and their allies, and to show that this stands in relation with another remarkable development, namely (not the occurrence, but) the absence of conjugation.
I
(2) As mentioned by Professor Minchin in his last Report [Cd. 7796], I have been engaged, with the assistance of Miss O. Lodge, B.Sc., in working out the para- sitic protozoa collected by Surgeon Atkinson in the "Terra Nova" Expedition. have not been able to give as much time as 1 should have liked to this work, which is still in progress. There are one or two interesting new protozoa in the material, notably a large ciliate, parasitic on the baleen plates of a whale, which is very remarkable in that it feeds on the red blood-cells, its endoplasm being sometimes crammed with these. We have got several stages in the life-history, but I do not I hope to give propose to describe these more fully until we have worked them out. fuller details about this work some subsequent time.
I desire to mention here, although it does not strictly come within the purview of this report, that, about the end of last July, I was asked to help in the diagnosis of various flagellates occurring in cases of dysentery among soldiers at the King George Red Cross Hospital who had been invalided from the Dardanelles. I was able to be of assistance in this connexion, and as it became evident that infections with protozoa, including malaria, were by no means infrequent, I offered to under- take the protozoological work there. My offer was accepted, so that a considerable portion of my time is now spent there in doing the examinations.
Departmental Work.-Naturally, the number of workers in the laboratory since We have the war broke out shows a diminution as compared with normal times. had no workers from abroad, all Royal Army Medical Corps and Indian Medical Service officers being, of course, otherwise engaged.
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In connexion with the war we have to deplore the loss of Lieutenant C. H. Martin, M.A., killed in action, who was one of the best protozoological workers All who whom it has been our privilege and pleasure to have in the laboratory. were at any time associated with him greatly regret the early termination of a valuable life.
Miss O. Lodge, of the Birkbeck Institute, worked regularly in the laboratory on certain days up till the end of May, when she left in order to undertake entomo- logical work temporarily with Professor Lefroy. In addition to working on the Terra Nova" material, she continued her research on the flea-leptomonads (Lepto- monas pattoni) in connexion with rats, endeavouring to obtain an infection in the latter (vide Professor Minchin's Report, Cd. 7796). During the whole period she has never found any stages of the parasites in the rats, and never obtained a single convincing instance of an infection of fleas allowed to feed upon rats which had previously been given every opportunity to become themselves naturally infected. watched her work with interest, and it has certainly given me the impression that infection of rats with this leptomonad, in a Leishmania-like form, must be very rare in nature.
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Miss R. Schwab and Miss Turner, of the Bedford College for Women, who are taking as a special subject for their Final Honours Examination at London Univer- sity, "Protozoa with special reference to Parasitic Forms," attended the lectures and studied this subject regularly in the laboratory from the beginning of January. Miss Schwab left about the end of April, to take up a post at the Rotham- sted Agricultural Experimental Station, but Miss Turner remained with us until the long vacation.
Mr. E. J. Sheppard has been working on cytological problems generally, in his spare time, since the beginning of February. He is studying particularly the cycle of the gonads in the larva of the rat-flea.
Mr. E. Heron-Allen availed himself of the facilities of our laboratory for a short time during the early spring, in connexion with his studies on Foraminifera.
Towards the end of the period under review Mr. M. Denne consulted us with reference to particular investigations on Monocystis, which he was desirous of taking up, and, I may add. is now studying certain little-known phases of the life- cycle of this parasite in the laboratory.
During April I was in correspondence with Mr. W. A. Willes, of Bourne- mouth, with reference to a disease of flat-fish in the River Avon which was then prevalent. I was able to diagnose the infection as due to the peculiar parasite Lymphocystis johnstonei, first described by myself some years ago, and to suggest what might perhaps best be done to combat the same.
H. M. WOODCOCK. September, 1915.
LIST OF PUBlications relating to INVESTIGATIONs carried on AT THE UNIVERSITY Department OF PROTOZOOLOGY.
By Professor E. A. Minchin :-—
(1) The Rat-Trypanosome, Trypanosoma lewisi, in its relation to the Rat-Flea, Ceratophyllus fasciatus. Quarterly Journal of Microscopical Science, vol. 60, pp. 463-692, plates 36-45.
(2) Critical Review of; Nöller, "Die Uebertragungsweise der Rattentry- panosomen," in Arch. Protistenk., vols. 25 and 34, 1914. Tropical Diseases Bulletin. vol. 5, pp. 318-323.
(3) Some Details in the Anatomy of the Rat-Flea, Ceratophyllus fasciatus. Journ. Quek. micr. Cl., vol. 12, pp. 441-464, plates 26-32.
By Dr. H. M. Woodcock :-
(4) Studies on Avian Hæmoprotozoa, No. III., Observations on the develop- ment of Trypanosoma noċtuæ (of the Little Owl) in Culex pipiens; with remarks on the other parasites occurring. Quarterly Journal of Microscopical Science, vol. 80, pp. 399-433, plates 29-31.
(5) On the occurrence in certain cases of a definite transmissive phase of a Trypanosome in the Vertebrate host, Arch. Protistenk., vol. 35, pp. 197-199.
(6) Protozoa. Zoological Record, vol. 50, 56 pp.
By Dr. H. M. Woodcock and Mr. G. Lapage :-
(7) Observations on the Life-Cycle of a new Flagellate. Helkesimastiz fæcicola, n.g., n. sp.: together with remarks on the question of syngamy in the Trypanosomes. Proceedings of the Royal Society, vol. 88B, pp. 353-370, plates 13 and 14.