COMPLEX SMUTS. 91 



allied to the preceding, are included botanically 

 under tlie genus called Polycystis, in allusion to tlie 

 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 pompJiolygodeSj 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 first, and ultimately burst in an 

 in*egular 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 cells, 

 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- 



* RaLenhorst has proposed Urocystis as the name of this 

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

 genus of Alga3. 



