462 



NATURE 



[December 24, 1914 



have extended to these students, many of whom are 

 for the present quite without funds, cannot bo left 

 out of account. In regard to the Jewish students, 

 who form a large proportion of the whole, and who 

 are mostly Russian subjects studyinj^;' at Li^ge or 

 Ghent, valuable help has been receiv(>d from the 

 Central Jewish Committee. 



This effort, however j^reat the tax it imposes on the 

 colleges, is worth making. It will enable Belgians 

 who are medically unfit to go on active service, and 

 Russians whose military service begins at the end of 

 their university career, to obtain their professional 

 qualifications during the war, and thus fill the depleted 

 ranks of doctors and engineers in their respective 

 countries. It will also spread a knowledge of Eng- 

 lish university education on the Continent, and not 

 improbably make the University of London an inter- 

 national, as it is already an Imperial, centre of univer- 

 sity education. 



the production at will of either 

 fungus-germs, flagellate monads, 

 or amcebm from the ultimate 

 segments of small masses of 

 'zoogl(f:a. 



A N illustrated article dealing with this question of 

 ■^^ the heterogenetic origin from small Zoogloea 

 masses of Fungus-germs, Monads, or Amoebae, written 

 by me, appeared in Nature of November 24, 1904. That 

 article was prepared at short notice in consequence of 

 a short letter on "Archebiosis and Heterogenesis," 

 which appeared a fortnight previously, and at a time 

 when I was not specially working at this subject. 

 Of late I have been doing much work in this direc- 

 tion, and have made out many very important new- 

 points, and can now speak with more precision con- 

 cerning the changes generally, and the modes of 

 obtaining- them. 



My results w-ere received with great scepticism, and 

 no bacteriologist has been induced to attempt either to 

 confirm or refute them. The possibility of "infec- 

 tion " has so dominated them, that they have refused 

 to consider the question. Of late, how-ever, three 

 bacteriologists have accepted my request that they 

 should allow me to demonstrate to them my position 

 by their examination of actual specimens. This they 

 did, separately, and as a result neither of them was 

 able to doubt that the Fungus-germs, the Monads, 

 and the Amoebae were, in truth, derived from the 

 ultimate segments of the Zoogloeal masses ; nor did 

 they suggest that the very similar developmental 

 changes to be seen in hundreds of Zoogloeal masses 

 taken from their respective scums could possibly be 

 accounted for by "infection." 



Only one of my friends had any interpretation to 

 suggest in opposition to my own. He started the 

 supposition that w-hat appeared to be bacterial aggre- 

 gates might "possibly," in spite of their appearance, 

 not actually be of that nature. He suggested that, 

 thoup-h taking the guise of bacteria, and though all 

 were similar in appearance, they might nevertheless 

 be some hitherto unknown progenitors of Fungus- 

 germs, of Monads, and of Amoebae which had aggre- 

 gated as Zoogloeal masses, and subsequently given 

 rise to their respective products. 



This wild supposition may, at all events, be taken 

 as an indication that its author could not doubt the 

 fact of the different products coming from the ulti- 

 mate segments, or imagine that " infection " could 

 account for what he had seen. It was started by one 

 who was absolutely opposed to the very notion of 

 heterogenesis;- He was subsequently able to find abso- 

 lutely no support for his "possibilities," and after a 



NO. 2356, VOL. 94] 



futile search frankly admitted that only bacterial 

 Zooglceas were known, apart possibly from others of 

 an algoid type. 



The current notion among bacteriologists concern- 

 ing the nature and mode of origin of Zoogloeas is that 

 adopted by R. Muir in the article, " Bacteriology," in 

 the last edition of the " Encyclopaedia Britannica " 

 (vol. iii., p. 161), in which he says: — "The Zoogloea 

 is now known to be a sort of resting condition of the 

 Schizomycetes, the various elements being glued 

 together, as it were, by their enormously swollen and 

 diffluent cell-walls becoming contiguous." 



But bacteriologists do not seem ever to have 

 examined the small masses that form in the scum 

 on the surface of a hay infusion. I have been unable 

 to find any reference to them, or of processes of seg- 

 mentation occurring in any other Zoogloeas. I cannot 

 think that those with which we are now concerned 

 are formed in the manner above indicated. All the 

 evidence seems rather to show that as the bacteria 

 lapidlv multiply thev also excrete the jelly-like gloeal 

 material in which they are subsequently found to be 

 imbedded. 



Preparation of the Infusions. 



One of the important new points recently ascer- 

 tained is that I can prepare two small infusions at the 

 same time from the same sample of hay, and by 

 allowing- one to infuse for three hours at a tempera- 

 ture of 90° F., can feel confident that in the course of 

 three to five days the ultimate products of segmentation 

 of the Zooglceas that form can be made to yield 

 Monads or Amoebae ; while if the other is infused for 

 the same time at 98° F. no Monads or Amoebae will 

 appear, and the ultimate Zoogloeal segments, though 

 formed, and very similar in appearance, will remain 

 apparently stationary for eight to thirteen days, and 

 then begin to show themselves as multitudes of brown 

 Fungus-germs. 



It is best to use comparatively new hay, and not 

 that of the previous season. I take a small portion 

 and having cut it into ^-in. lengths, place it in 2-oz. 

 beakers to which water is added just sufficient to cover 

 it. The proportion of the two I have found to be 

 a little more than 30 grains, to the ounce of water. 

 As soon as the infusions have been made they are 

 filtered through No. o Swedish paper (so as to exclude 

 encysted Kolpodae and the great majority of Fungus 

 spores) into common one-ounce porcelain pots, until 

 they are about half-full — the depth of the infusion 

 being then only a little more than half an inch. The 

 scum which ultimately forms will be thin, and there- 

 fore much more favourable for examination than if it 

 had been thick and formed over a greater depth of 

 infusion. The covers are replaced on the pots, and the 

 dates and temperatures at which the infusions have 

 been made are marked thereon. These covered pots 

 are then mostly kept at room temperature, 62°-64° F. 



Examination of the Scum or Pellicje. 



The pots are not usually opened until two days have 

 elapsed, as it would be only during the last twelve 

 hours that any verv distinct scum begins to Form, and 

 that a few verv small Zoogloeas may be found scat- 

 tered through it. By the end of the third day the 

 Zoogloeas may be very numerous, and will be found 

 to vary much in size and shape. An example illus- 

 trating a rather later stage is shown in Fig", i, in 

 which the little masses are seen to be extremely 

 numerous. Many of these early Zoogloeas already 

 show primary processes of segmentation. 



In order to examine the scum a small portion is 

 taken up on the point of a scalpel and rotated off on 

 to a drop of distilled w-ater. If thereafter it should 

 be desired to preserve the specimen some 5 per cent. 



