29^ Tilii MICROSCOPE. 



represents a vertical section of a leaf of black-currant, in- 

 fested with jEcidium grossularice ; its spermogonia are 

 seen on the surface, and the perithecia below. The genus 

 Sphoeriacei (jSTo. 3, Plate I.), common enough on most 

 herbaceous stems, first seem to be little black spots, a ; 

 when examined more closely are found to resemble little 

 brownish bottles, 6, filled with rolls of spores. Other in- 

 structive specimens are — ' 



Cystopus candidus (Uredo olim), Crucifer White-rust; 

 conidia equal, globose ; membrane equal, ochraceous ; 

 oospores sub-globose, epispore yellowish-brown, with irre- 

 gular obtuse warts j warts solid. On shepherd's puise, 

 cabbage, and other Crucifer?e : receptacle consisting of 

 thick branched threads ; conidia concatenate, at length 

 separating ; oospores deeply seated on the mycelium. — ■ 

 Fhyllactinia guttata (Olim Erysiphe). Plate I. ISTo. 9. 

 Hazel Blight ; amphigenous ; mycelium web-like, often 

 evanescent ; conceptacles large, scattered, hemispherical, 

 at length depressed; appendages hyaline, rigid, simple; 

 sporangia 4-20, containing 2-4 spores. On leaves of haw- 

 thorn, hazel, ash, elm, &c. — Aregma (Phragmidium) hul- 

 hosum. Plate I. Xo. 20. Bramble Brand ; hypogynous, 

 Avith a dull red stain on the upper surface ; spores in 

 large tufts, 4-septate, terminal joint apiculate; peduncles 

 incrassated, and bulbous at the base. — P^iccinia variabilis, 

 Variable Brand ; sori amphigenous, minute, roundish, sur- 

 rounded by the ruptured epidermis, nearly black ; spores 

 variable, obtuse, cells often subdivided ; peduncle very 

 short. On leaves of dandelion. — Puccinia biui, Box Brand. 

 Plate I. Xo. 17. Sori sub-rotund, convex, and scattered; 

 spores brown, oblong, rather strongly constricted, lower 

 cell slightly attenuated ; peduncle very long. On both 

 surfaces of box leaves : spores uniseptate, supported on a 

 distinct peduncle. Plate I. No. 18. — Trichobasis (Uredo 

 olim) senecionis, Grotmdsel-rust ; spots obliterated; sori 

 solitary or regidarly crowded ; sub-rotund and oval, on the 

 under surface, surrounded by the ruptured epidermis; 

 spores sub-globose, orange. On various species of groundsel : 

 spores free ; attached at first to a short peduncle, which 

 at length falls away. 



It appears that at particular periods of the year the 



