DIMOEPHISM IN FUNGI. 139 



Another Fuccinia, P. phragmitis, also abundant on the 

 common reed, had its jecidiospores on various species of Rwnex. 

 Several others are referred to in the same paper, which I need not 

 enter into. Space prevents entering on any further examples, and 

 one can only refer in passing to the interesting fungus, Isaria, 

 growing on grass, etc., and its perfect form of Cordiceps and Torru- 

 bia, one species of which is parasitic on the truffle and another on 

 the pupte of moths and other insects. But I wish, in conclusion, 

 to refer to the lowest form of fungi, viz. — the Schizophyta or Bac- 

 teria. Professor Ray Lankester, in the April number of the 

 Quarterly Journal of Microscopical Science for 1886, has a paper 

 on the Pleomorphism of the Schizophyta, the object of which is 

 to show that he had, in a paper published twelve years ago, put 

 forward the view of the subject that is now being generally 

 accepted. 



He discovered a peach-coloured bacterium, which exhibited a 

 wide range of forms, connected by intermediate forms, growing 

 together in the same vessel, and linked together most unmistake- 

 ably by the fact that they were all coloured by a special pigment. 

 He observed this organism on many occasions, and from various 

 localities he obtained some modifications of form by cultivation, 

 but chiefly depended on the association of the different forms, the 

 presence of completely transitional forms, and the common bond 

 of pigment, for the views as to their nature which he put forward. ' 

 Cohn had just then put forward the view that Micrococcus, Bacte- 

 rium, Bacillus, Vibrio, Spirillum, and Leptothrix were different 

 genera. Lankester regarded them as form phases, or variations of 

 growth, of a number of Protean species, each of which might 

 exhibit, according to undetermined conditions, all or some of 

 these forms ; and that the existence of true species must be char- 

 acterised, not by their simple form-features, but by the ensemble of 

 their morphological and physiological properties, exhibited in their 

 complete life -histories. He then says that this view, which he put 

 forward in 1873, is precisely that which is espoused by Prof, de 

 Bary in 1884, when he writes, in his work on the comparative 

 morphology of fungi, " Strictly-made morphological and develop- 

 mental researches are now to hand. They have demonstrated 

 that the forms known as cocci, rods, threads, etc., are phases of 



