8o 



NA TURE 



[November 24, 1904 



ming 1 



way comparable to the convincing evidence above adduced 

 concerning the heterogenetic origin of Monads from the 

 transformation of Zooglcea masses — a transformation in 

 which we have vegetal organisms giving rise to animal 

 organisms of a totally different kind, though between these 

 two forms of life no relation of kinship has ever been 

 admitted, or even suspected, by the great majority of 

 biologists. 



Origin of Fungus-germs from Masses of Zoogloea. 



It has seemed to me, as I have said, impossible to say 

 from the mere microscopical characters of the masses of 

 Zoogloea whether they are likely to yield Monads or Fungus- 

 germs. It will be observed, however, that in the three 

 cases to which I have just referred the masses giving rise 

 to embryo Monads have all been small, and that they have 

 tended to go through their metamorphoses with some 

 rapidity. 



It is certain, however, that the great majority of the 

 larger Zoogloea masses tend rather to produce Fungus- 

 germs of one or other kind, and to go through their changes 

 at a slower rate. These statements may be illustrated by 

 a record of the changes taking place in the larger Zooglcea 

 masses that were found in great abundance in the pellicle 

 forming on infusion A. These larger masses of Zoogloea, 

 and also all the later changes which I am now about to 





Fig. 9.- 





nt of small brown Fiingus-gerrr 

 ( X 500). 



s of Zoogic 



describe, were, however, wholly absent from the pellicle on 

 infusion B, up to the eleventh day.' 



Where the changes occur to which I would now direct 

 attention the Zooglcea masses gradually become larger and 

 much more refractive, vi'hile they also stain much more 

 deeply with logwood, gentian violet, or other of the aniline 

 dyes. At the same time the constituent bacteria, which 

 are so very distinct in the early stages, seem to become 

 enlarged and gradually more or less hidden as the mole- 

 cular changes taking place in the mass increase. One of 

 these aggregates in this refractive, glistening stage, which 

 was found and photographed on the fifth day, is shown in 

 F'g. 7 tX375)- 



The next stage of change is revealed by distinct indica- 

 tions of segmentation beginning to show themselves through 

 the mass, such as may be seen in Fig. 8 (X500), which 

 represents a portion of a large Zooglcea mass that was 

 found on the sixth day. This condition may persist for 

 several days, but occasionally further changes occur 

 rapidly, as may be seen by Fig. 9 (xsoo), showing a 

 portion of another large Zooglcea mass found on the seventh 

 day, in which minute ovoid germs of different sizes are 

 1 See note on p. 78. 

 NO. 1830, VOL. 71] 



separating from the mass, and at the same time assummg 

 a brown colour. This change was proceeding more rapidly 

 at the edge of the mass ; but further in, as may be seen 

 in the upper portion of the figure, the mass shows more 

 of the appearance to be seen in Fig. 8. Although the germs 

 seem to separate from the metamorphosed Zooglcea mass 

 as bodies of varying size, I think there can be no doubt that 

 some of the separate units siibsoquentlv increase distinctly in 



-A portion of the bri 



nycelium(x,:5). 



size — though whether they undergo segmentation is not so 

 clear. On the following day numerous heaps of brown 

 l''ungus-germs were found derived from these Zoogloea 

 masses, forming clusters so thick and dense that their con- 

 stituents could only be shown by pressing upon the cover 

 glass firmly and thus breaking up the masses of germs. 

 Portions of such a broi^en up mass are represented in 

 Fig. II, A (X500). 



As a rule, these bodies show little tendency to germinate. 



from, the mycelium ( X 500). 



but occasionally they do so, and two or three masses of 

 mycelium to which they had given rise (also of a brown 

 colour) were found on the eighth day. One of them had 

 sent a hvpha above the surface, and there produced a great 

 number of ovoid acrospores having a bluish-black appear- 

 ance. Some of the mycelium is shown in Fig. 10 (X125), 

 while the acrospores are represented in Fig. 11, B (xsoo). 



