Classification of the Schizomycetes. 77 



almost incredible. One writer, Carnoy, even carried the 

 doctrine to the only rational conclusion which could be 

 deduced from such kind of observations as then existed : 

 he assertecLthat every species of Fungus, cultivated under 

 suitable conditions, could be transformed into Penicillium ! 

 But later investigators, e.g. Van Tieghem, throw grave 

 doubts upon the accuracy of even De Bary's observations, 

 and he himself (" Beitrage," iv. i) seems to admit that he 

 was mistaken. 



There are, however, many cases of pleomorphy in Fungi, 

 which may be considered as proven. We have only to refer 

 to the recent victorious establishment of the pleomorphism 

 of the Uredines, and it is natural to expect that similar 

 cases exist in other groups. But here we may learn another 

 lesson. Not every Puccinia passes through the three stages 

 which are typical of a Uredinous fungus; some occur in 

 one form alone, so far as our present knowledge goes. The 

 same may be expected to be the case with the Schizomy- 

 cetes. Even if we grant that some of them do pass through 

 a number of different forms, which have been hitherto 

 described as genera, it need not be inferred that there are 

 no distinct Micrococci, no independent Spirilla. In fact, 

 as evolutionists, considering that we are here dealing with 

 the simplest forms of life, we might anticipate that many 

 of the species would remain permanently, by arrest, in forms 

 which are mere stages of development of those more highly 

 evolved. Moreover, though one stage of Cladothrix dicho- 

 toma may resemble Bacterium Termo in outward form, as 

 Zopf asserts, it by no means necessarily follows that they 

 are identical. There may be differences between them of 

 which we have as yet no cognisance, for little is known 

 of the internal constitution of the Bacteria. What is 

 wanted now is a thorough and searching investigation of all 



