235 



POLYMORPHISM IN FUNGI.* 



G. MASSEE. V.M.H., etc., 

 Kci.'. 



Nowhere else in the Vegetable Kingdom do we meet with such 

 sharply differentiated stages, collectively constituting an 

 individual, as are to be met with in some groups of Fungi. 

 Such stages of an individual are, in many instances, so markedly 

 dissimilar in general appearance, structure, and mode of 

 life, that in past times they were respectively looked upon as 

 entities or species, containing an individuality of their own, 

 and were considered as constituting distinct genera belonging 



Srom). 



Thielavia basicola Zopf. — i, first conidial {Milowia) stage 2, second 

 conidial [Tonila) stage ; 3, Perithecium or fruit of the highest or ascigerous 

 stage ; 4, ascus containing eight spores, produced in the perithecium. 

 Figs. I, 2 and 4, mag. 400 times ; Fig. 3, mag. 50 times. 



to widely separated families. Numerous fungi consist of two 

 or three such stages in their complete life-cycle, others have 

 half-a-dozen or more. 



* Address dehvered at the Annual Fungus Foray, held at Sandsend. 

 See 'Naturalist, Jan. igog, pp. 2i-2g, 



1909 June I. 



