SPH^RIA. 



[ 584 ] 



SPELERIACEI. 



fine powder. Many of the immersed kinds 

 are only evident externally as minute black 

 points or dots upon the surface of the leaf, 

 stem, &C.., which they infest ; others are ex- 

 posed freely when mature, breaking out from 

 beneath the epidermis. Sometimes they are 

 solitary, sometimes associated in small or 

 large numbers, distinct or confluent. 5. qua- 

 ternata (fig. 651) is an example of the oc- 

 currence of free perithecia grouped together, 



Fig. 651. 



kfB5^S?9( 



,. ,. 



Sphseria quateruata. 



Three groups growing on a piece of beech- wood. 



Magnified 20 diameters. 



mostly in fours; being decumbent, their 

 ostioles are collected together, and they per- 

 forate the bark by a little black rugged tu- 

 bercle. This is common on beech-trees. 

 S. convergens (figs. 652, 653) is an analogous 



Fig. 652. 



ftitoimq afoi _^ 

 ,aoJ 

 fono'J 



Sphseria convergens. 

 Magnified 20 diameters. 



Fig. 654. 



Sphaeria verrucosa. 

 Magnified 20 diameters. 



form. S. elonyata (figs. 660-662) affords an 

 example of those species which are at first 

 immersed and adnate, and finally burst forth 

 and become nearly free. 



For species now separated from this genus 

 see CLAVICEPS, HYPOXYLON, XYLARIA, 

 HYPOCREA, and NECTRIA. 



Certain points of great interest have lately 

 been ascertained respecting this genus and 

 its allies, which are mentioned under the 

 heads of the family and other genera, namely 

 the coincidence and evident connexion be- 

 tween true species of Sphceria and various 

 Coniomycetous Fungi ; for just as Melasmia 

 is a precursory form of Dolhidea, Tubercu- 



laria of Nectria, &c., Cytispora, Septoria, 

 and other forms precede Sphceria, and many 

 distinct stylosporous forms are associated, 

 usually described as belonging to distinct 

 genera, such as Stilbospora, Sporocadus, 

 Sphceropsis, &c. Thus these plants seem to 

 produce three kinds of reproductive organs, 

 as is now known to be the case with the 

 Uredines, viz. 1. a form analogous to the 

 spermogonia of the Lichens (in Sphceria re- 

 presented by Cytispora, &c.); 2. an ascopho- 

 rous fruit, the perithecium of the true Sphceria ; 

 and 3. a stylosporous fruit, representing the 

 genera Stilbospora, Sporocadus, &c. 



S. Laburni has been found by Tulasne to 

 exhibit all these stages, namely perithecia 

 containing asci, surrounding a cytispore, with 

 other conceptacles on the same stroma re- 

 sembling the perithecia, but lined with sty- 

 lospores instead of asci. Berkeley and 

 Broome also describe the existence of the 

 perithecia of Sphceria inquinans and the con- 

 ceptacles of Stilbospora macrosperma on the 

 same stroma (PL 20. figs. 25-28). 



It is stated by Tulasne that the 'spermatia' 

 of the cytisporous forms may be contempora- 

 neous with the stylospores or basidiospores, 

 but they always precede the ascospores in 

 their development ; hence there is ground 

 for supposing that they represent the sper- 

 matozoids of the higher Cryptogamia. With 

 regard to the relations of the stylospores, it 

 is possible that they are merely modifica- 

 tions of the ascospores; but it w T ould appear 

 probable that they must be regarded as real 

 gonidial structures, for which it may be de- 

 sirable to retain Fries's name of conidia, 

 just as that of tetraspores is retained among 

 the Florideous Algae. Attention should be 

 directed here to the complete correspondence 

 between the series of forms of these genera 

 and those of the UREDINES, where, as in 

 PUCCINI A, we have the spermogonia (cyti- 

 spore), the uredo (stylosporous fruit), and 

 the perfect fruit (perithecium). 



Mr. Currey has recently published some 

 observations on the germination of the spores 

 of the Sphcerice. 



BIBL. Berk. J Bn7.FZor.ii.pt.2.p.232; Ann. 

 Nat. Hist. i. p. 205, vi. p. 360, ser. 2. v. 

 p. 374, vii. p. 186, Hook. Journ. Bot. iii. 

 p. 319 ; Fries, Summa Veg. 388, Syst.Mycol. 

 ii. p. 319; Tulasne, Ann. des Sc. nat. 3 ser. 

 xv. p. 375 (Ann. Nat. Hist. ser. 2. viii. p. 

 117) ; Currey, Mic. Journ. iii. 263 (1855). 



SPH J3RIACEI. A family of Ascomyce- 

 tous Fungi, containing a vast number of 

 mostly epiphytic plants, of minute dimen- 



