genus, under the name of Oomyces, on account of its egg-shape. 

 Madame Libert published it in her exsiccata, as Sphseria cameo- 

 alba Libert. It is about a line high, bluntly conical, and of a 

 pinkish-yellow colour ; there is an outer, leathery receptacle, trun- 

 cate at top, around the centre of which are four to seven dark 

 dots ; a cross section shows that these are the mouths of as many 

 delicate, membranous perithecia which are closely packed in the 

 outer conceptacle. The perithecia contain a number of elongate, 

 cylindrical, asci, filled with very long, iiexuous sporidia. It has been 

 placed in a new genus on account of its compound character ; the 

 outer conceptacle containing free, ascigerous perithecia. In 

 Pleospora herbarum Pers. and P. polytricha Wallrotli., belonging to 

 the section Denudatae of the genus Sphseria, the early states were 

 considered autonomous plants; but it has been demonstrated that 

 the cQnidia of the first constitute the genus Mystrosporium of 

 Desmaziere, which again appears to give origin to Cladosporium 

 herbarum Link., a common pest in greenhouses, covering the plants 

 with a sooty stratum. The conidia of the latter, Pleospora polytricha 

 Wall., being stipitate, and septate, present an elegant appearance 

 under the microscope, and probably belong to Acrothecium 

 simplex B. and Br. Nectria cinnabarina Fr. the conidiiferous state 

 of which is known as Tubercularia vulgaris Tode., is interesting, 

 from its common occurrence on dead sticks, covering them with 

 bright, scarlet spots. Another of the same genus Nectria 

 inaurata B. and Br. has two forms of ascigerous fruit, a very unusual 

 occurrence ; it grows on dead twigs of holly. Capnodium and its 

 allies, as Fumago and others, belong to the Sphseriacei since they 

 produce their more perfect form of fruit in asci, their perithecia 

 being furnished with a round mouth. To the unassisted eye these 

 plants appear as a mere sooty stain on the leaves of trees and 

 shrubs, thus spoiling their appearance. We may mention in this 

 place that the conidiiferous state of Hypoxylon coccineum BuU. 

 was described by Persoon as a mould under the name of Isaria 

 farinosa Pers. ; but it has been since traced to the Hypoxylon, it is 



