214 Dr. 11. Charlton Bastian on the ITeterogenetic 



(c) Zoogloea uncoloured, undergoing partial segmentation, 

 and then tlie origination therefrom of Fungus-germs gradually- 

 becoming brown, as in figs. 8 and 9 in ' Nature ' for Nov. 24th, 

 1904. 



{d) Zooglcea uncoloured and undergoing partial segmenta- 

 tion ; these segments tlien becoming brown, and subsequently- 

 being transformed into groups of brown Fungus-germs, as in 

 figs. 2, A, and 4, B. 



(e) A mixture of the last two processes, as shown to some 

 extent in the lower part of fig. 9 (' Nature,' Nov. 24th) . 



(/) Zoogloea uncoloured and undergoing complete segmen- 

 tation into colourless units, which gradually- assume a brown 

 •or brownish-black tint, as in fig. 12 (' Nature,* Nov. 24th). 



As I previously said, the conversion of the Zoogloea masses 

 into aggregates of Monads takes place much less frequently 

 than their transformation into Fungus-germs. Still the two 

 processes may often be seen going on side by side in the 

 pellicle. I am, indeed, disposed to think from what I have 

 seen that some of the same kind of Zoogloea masses which in 

 the early days become converted into Monads may, if they 

 chance to remain untransformed for seven or eight days, be 

 then converted into Fungus-germs rather than into Monads. 

 It is difficult to be certain of this, but I am strongly disposed 

 to believe that it is so. It is quite certain, however, that 

 conversion into Monads, when it occurs, takes place almost 

 always somewhere between the third and the fifth days, while 

 after the latter date up to the tenth or twelfth day one finds 

 Zoogloea masses either all brown or producing brown segments 

 which are being converted into Fungus-germs. The Zoogloea 

 masses and all the segments into which they divide invariably 

 remain colourless where Monads or Amcebai are to be the 

 products. 



Since my former communication to ' Nature* I have seen 

 enormous numbers of the Zoogloea masses yielding Monads in 

 the pellicle on an infusion of hay, which was exposed to light 

 in a small beaker. The Monads were met with on the fourth 

 and fifth days, the temperature to which the infusion had 

 been exposed having varied from about 54°-59° F. (12°-15° 

 C.)- Ihe Zooglcea masses were in many cases very large and 

 presented some peculiar characters. In their early stages they 

 always appeared as pellucid, somewhat ramified, discontinuous 

 areas, as shown in fig. 5, A (PI. XV.). Later, portions of the 

 mass begin to segment as in B ; later still, actual Monads 

 may be seen begirniing to form, as in fig. 6, A ; while, finally, 

 there is a more complete conversion into an aggregate of 



