464 



NATURE 



December 24, 1914 



dependent upon the temperatures at which tlie pois 

 are kept.' 



The actual mode of production of the Fungus- 

 germs from the bacterial aggregates may be seen in 

 Figs. 3-5. A portion of a Zoogloea lightly stained 

 with C. fuchsine is shown in Fig. 3, in which the 

 bacteria are remarkably distinct, and where here and 

 there they are becoming enclosed within distinct cell- 

 walls. \Ve see, in fact, a free cell-formation going 

 on, in which the bacteria become the nuclei, and these 

 nuclei undergoing division. Fig. 4 shows other 

 stained specimens illustrating the mode in which seg- 

 mentation progresses from multibacterial aggregates 

 in A to multinuclear masses in B, which lead on in 

 C to separate ultimate products in the form of 

 nucleated Fungus-germs. 



In Fig. 5 we have to do with unstained specimens 

 gradually assuming a brown colour. In A the three 

 pale masses show early stages in which the Fungus- 

 germs are forming, in situ, in fairly large segments; 

 Avhile 'the dark masses arounfl nro aggregates of 



Fig. 4. — X5C0. 



brown, fully formed Fungus-germs. In B we have 

 a more ill-defined Zoogloea, in which careful examina- 

 tion will reveal portions becoming more and more 

 distinct, until thev end with groups of large well- 

 defined brown Fungus-germs. 



We have here then a direct free formation of cells, 

 the existence of which has so long been doubted, 

 where bacteria constitute the nuclei, and the altered 

 gloeal material the remaining portions of the cell- 

 protoplasm. What is so plainly to be made out in 

 Figs. 3 and 4 seems generally to occur when Fungus- 

 germs are formed in and from Zoogloeas ; and the 

 mode in which segmentation is so clearlv shown to 

 progress in Fig. 4 probably holds good for all other 

 Zoogloeas, even when the ultirpate products are of a 

 wholly different order 



In all cases the Fungus-germs produced in the 

 manner I have shown, though they multiply to some 

 extent so as to form small heaps or short chains, 

 remain as such for very many days, and require to 



1 Where the infusion has been made at a higher temperature, such as 

 ioo'-io2' F., the appearance of the brown Fnngus-germj may be still further 

 delayed. What I have to say in this communication re'ers only to the pro- 

 ducts from the Zooeloeas that may be found within the first fourteen days. 



NO. 23'^6, VOL. Q4I 



be much coaxed in order to undergo further develop- 

 ment with production of hyphae. 



Conversion of L'liimate Segments of Zoogloeas inio 

 Flagellate Monads. 



Where the infusion has been prepared for three 

 hours at 90° instead of at 98° F. the Zoogloeas which 

 form present no difference in appearance and in mode 

 of segmentation from what has been represented in 

 Fig. 2. 



There is, however, this remarkable difference, that 

 such masses never assume a brown colour, and their 

 ultimate products of segmentation begin to be visibly 

 transformed in three or four rather than in from eight 

 to thirteen days, and then they reveal themselves as 

 rapidly increasing swarms of flagellate Monads. 



These ultimate segments appear at first as little 

 spherical, motionless bodies, such as are shown dis- 

 persed at the edge of a portion of scum in Fig. 6, A, 

 and also aggregated as ultimate products of a small 



Fig. 5.— X700. 



mass in 6, B, though they are there somewhat obscured 

 b)' a few overlying bacteria. A smaller aggregate of 

 motionless units is represented above, while below, 

 before the running in of some formalin solution, some 

 of the bodies shown were active Monads. 



These Monads always contain a few granules, such 

 as are shown in 6, C, in the lower body on the right, and 

 a quite small nucleus is also frequently recognisable 

 in such early units. Slight variations in size and 

 shape of the Monads are met with from different 

 samples of hay, just as different kinds of Fungus- 

 germs are also produced. They have generally two 

 flagella, though one of those that I succeeded in 

 photographing (Fig. 6, C) has three. I have never 

 previously been able to get any tolerable photograph 

 of these iMonads ; this time I was to some extent suc- 

 cessful with the aid of eosin. All other dyes or pre- 

 servatives have proved useless, owing to the extremely 

 delicate structure of the Monads. At times when a 

 slide has been under examination for a rather long 

 time, some of the Monads have become quiescent, and 

 then I have often been able to recognise a contracting 



