COMPLEX SMUTS. 91 



allied to the preceding^ are included botanically 

 under tlie genus called Polycystis, in allusion to the 

 many cells of which the spores are composed.* In 

 the most recent work on British Fungi^ approxi- 

 mating to a Flora — viz.^ ^^ Berkeley's Outlines '^ — 

 only three species are recorded^ whilst the most 

 common^ at least around London^ is omitted in 

 error ; for it could scarcely have been unknown as 

 indigenous to this country. This last is the crow- 

 foot smut {Polycystis porri'pholygodes, Lev.)^ found 

 on the leaves and petioles of the common creeping 

 buttercup {Ranunculus repens), distorting them 

 very much^ and also occurring on the wood- anemone 

 and some other Ranunculaceous plants. The leaves 

 and their footstalks^ when attacked^ become swollen^ 

 as if blistered at firsts and ultimately burst in an 

 irregular manner^ exposing a mass of blackish 

 soot-like dust (plate IX. fig. 183)^ which on exa- 

 mination will be found to consist of the many-celled 

 spores alluded to (plate IX. fig. 184). Each of 

 these spores appears to have a transparent outer 

 membrane^ either inclosing an unequal number^ 

 from two or three to five or six:^ distinct ceUs^ 

 compressed together into a spherical form by the 

 outer integument^ or the interior is divided by 

 septa into as many cells. Each of these divisions 

 contains a dark brownish endochrome, or cell- 



* Eabenhorst has proposed Urocystis as the name of this 

 genus, on the ground that Polycystis was priorly apphed to a 

 genus of Algse. 



