POLYMORPHISM. 207 



interested observer to this effect. " On a preparation preserved 

 in a moist chamber, on the third day a white speck was seen on 

 the surface, consisting of innumerable ' yeast ' cells, with some 

 filaments, branching in all directions. On the fourth day tufts 

 of Penicillium had developed two varieties P. glaucum and 

 P. mride. This continued until the ninth day, when a few of 

 the filaments springing up in the midst of the Penicillium were 

 tipped with a dewdrop-like dilatation, excessively delicate a 

 mere distended pellicle. In some cases they seemed to be 

 derived from the same filament as others bearing the ordinary 

 branching spores of PeniclHium, but of this I could not be 

 positive. This kind of fructification increased rapidly, and on 

 the fourteenth day spores had undoubtedly developed within the 

 pellicle, just as had been observed in a previous cultivation, 

 precisely similar revolving movements being also manifested."* 

 Although we have here another instance of Mucor and Penicillium 

 growing in contact, the evidence is insufficient to warrant more 

 than a suspicion of their identity, inasmuch as the equally 

 minute spores of Mucor and Penicillium might have mingled, 

 and each producing its kind, no relationship whatever have 

 existed between them, except their development from the same 

 matrix. 



Another case of association for the evidence does not proceed 

 further was recorded by us, in which a dark-coloured species 

 of Penicillium was closely associated with what we now believe 

 to be a species of Macrosporium but then designated a Spo- 

 ridesmium and a minute Sphaeria growing in succession on 

 damp wall-paper. Association is all that the facts warrant us 

 in calling it. 



We cannot forbear alluding to one of the species of SpJiaria 

 to which Tulasne f attributes a variety of forms of fruit, and we 

 do so here because we think that a circumstance so extraordi- 

 nary should be confirmed before it is accepted as absolutely true. 

 This refers to the common Sphceria found on herbaceous plants, 



* Lewis's "Report on Microscopic Objects found in Cholera Evacuations," 

 Calcutta, 1870. 



t Tulasne, "Selecta Fungorum Carpologia," ii. p. 261. 



