1879.] NATURAL SCIENCES OF PHILADELPHIA. 69 



supposed that the formation of septa is only the first step in the 

 process of germination; though unfortunately I can only conjec- 

 ture this, as the sporidia which I have tried to cultivate on slides 

 of moistened glass have thus far refused to germinate. 



From an examination of the above notes it will he seen that, 

 disregarding the somewhat variable ostiola, the various forms 

 above noted differ from each other only in the fact that in some 

 the perithecia are confluent and united in a partial stroma, while 

 in others they are scattered and without any distinct stroma. The 

 only question then is whether this variation alone is sufficient to 

 constitute a specific difference? Were this variability in the vege- 

 tative character accompanied by a corresponding variation in the 

 fruit, there "could be but one answer; but as has been already 

 stated, and as maybe seen by referring to the figures published in 

 Grevillea, and as 1 hope to show by the publication of actual 

 specimens in the North American Fungi, the fructification in all 

 these different forms is essentially the same. With just as much 

 reason might a specific distinction be made between the cluster of 

 culms sprung from a single grain of wheat planted in a good soil 

 and the single culm from another grain growing in a poorer soil. 

 This same variation in an allied species, Sphaeria gyrosa, Schw., 

 was not considered by Fries as by any means sufficient to war- 

 rant a specific distinction. In his Elenchus Fungorum, vol. ii. p. 

 84, under S. gyrosa, he says: " Erumpunt hoec tuberculosa com- 

 posita e rimis corticis Quercus ; sed in ligno decorticato, eadem 

 adest omnino simplex, conferta, subconfluens, punctiformis abs- 

 que stromate distincto ; singularis morphosis sed in hac tribu non 

 vara." These remarks apply as accurately, at least to the form 

 on- Bhus venenata,, i. e., to Dothidea venenata, C. & E., as if made 

 Avith reference to that particular case. If then these different 

 forms are to be united, it only remains to decide whether they are 

 to be referred to the genus Spheeria or to Melogramma or Dothi- 

 dea; or whether it would be better to follow 7 the example of some 

 of the transatlantic mycologists and create a new genus for this 

 particular case. But as the number of new genera, many of them 

 with characters sufficiently obscure, is every day increasing, it 

 would seem better to avoid this latter alternative. Throwing aside 

 next, in this case, the generic name of Sphseria, from which genus 

 the fungus under consideration may perhaps with propriety be 

 excluded on account of the peculiar character of its perithecia, 



