recognized. Fries divided them in the Systema according to 

 their simple, or compound habits. 



Those in the simple section are either innate in the bark of trees 

 or plants, or at length emergent by a longer or shorter neck, with 

 round or elongate mouths, or quite superficial on the surface of 

 wood or sticks, and these are glabrous, or hairy, or tomentose, and 

 sometimes seated on a shaggy subiculum. In the compound 

 section the perithecia are aggregated together in the substance of 

 wood, or leaves, or in the stems of herbaceous plants, assuming, 

 at times, a circinate or quincuncial arrangement, or occupying 

 carbonaceous receptacles which are immersed in the wood. Some- 

 times they are located in a flat, or globose, stroma, which, in the 

 more perfect species, assumes a simple or branched, erect form. 



To begin, however, with the more simple forms. We have in 

 them instances of species without any true perithecia as in 

 the genus Dothidea, where, however, that want is fully compen- 

 sated by the various forms of fruit which have been traced to it 

 in its early stages ; thus in Dothidea melanops Tul. there are 

 macrostylospores and microstylospores, as well as ascigerous 

 fruit. 



Again in Diatrype stigma Fr. Stictosphseria Iloflfmanni Tul, we 

 have conidia lining the interior of irregular cavities of the wood, 

 or bark, on which it grows j and, on the same stroma, ascigerous 

 conceptacles containing sporidia of a form very similar to the 

 conidia. 



In Cucurbitaria macrospora Tid. the three forms of fruit are again 

 to be seen, occupying one stroma. In Melanconis macrosperma 

 the conidia are shown, in Tulasne's figure, growing intermixed 

 with macrostylospores. The conidiiferous tufts of Stigmatea frag- 

 rarise also present us with a beautiful microscopic object; this species 

 grows on living strawberry leaves. I cannot pass over without 

 notice a minute plant, the structure of which is very curious. 

 It grows on the leaves of Aira csespitosa, a coarse grass known to 

 the Wiltshire farmers as Bull-polls, it has been described, as a new 



