POLYMOKPHISM. 205 



has substituted that of Torrubia* These curious fungi partake 

 more or less of a clavate form, and are parasitic on insects. 

 The pupse of moths are sometimes seen bearing upon them the 

 white branched mould, something like a Clavaria in appearance, 

 to which the name of Isaria farinosa has been given. According 

 to Tulasne, this is the conidia form of the bright scarlet, club- 

 shaped body which is also found on dead pupaa, called Torrubia 

 militaris. An American mould of the same genus, Isaria 

 sphirigum, found on mature moths,t is in like manner declared to 

 be the conidia of Torrubia sphingum ; whereas a similar mould, 

 found on dead spiders, called Isaria arac7inophila,% is probably 

 of a similar nature. An allied kind of compact mould, which 

 is parasitic on Cocci, on the bark of trees, recently found in 

 England by Mr. C. E. Broome, and named Microcera coceophila,§ 

 is said by Tulasne to be a condition of SpJicerostilbe, and it is 

 intimated that other productions of a similar character bear 

 like relations to other sphoeriaceous fungi. For many species 

 of Torrubia no corresponding conidia are yet known. 



Some instances might be noted, not without interest, in 

 which the facts of dimorphism or polymorphism have not been 

 satisfactorily proved, but final judgment is held in suspense 

 until suspicion is replaced by conviction. Some years since, a 

 quantity of dead box leaves were collected, on which flourished at 

 the time a mould named Penicillium roseum. This mould has a 

 roseate tint, and occurs in patches on the dead leaves lying upon 

 the ground ; the threads are erect and branched above, bearing 

 chains of oblong, somewhat spindle-shaped spores, or, perhaps 

 more accurately, conidia. When collected, these leaves were 

 examined, and nothing was observed or noted upon them except 

 this Penicillium. After some time, certainly between two and 

 three years, during which period the box remained undisturbed, 

 circumstances led to the examination again of one or two of the 

 leaves, and afterwards of the greater number of them, when the 



* Tulasne, " Selecta Fungornm Carpologia," iii. p. 6, pi. i. figs. 19-31. 

 + Cramer's " Papilio Exotic" (1782), fig. 267. 

 £ Cooke, " Handbook," p. 548, No. 1639. 

 § Ibid. p. 556, No. 16C6. 

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