Seed-vessels of Ferns, and Section of Limestone. 



Plate 2. 



I. Seed-vessel of Fern when unripe, magnified diameters. 2. Seed-vessel of Fern, at the 

 moment when the ring straightens itself. 3. Leaflet of Black Maiden-hair Spleen wort Fern. 



4. Two sori, or collection of seed-vessels, of Spleenwort Fern, magd. 12 diams. 5. Sorus of 



Hart's-tongue Fern, magd. 6 diams. 6 Part of a leaflet of Shield Fern. 

 7. Sorus, magd. 10 diams. 8. Sori of Polypody Fern, magd. 7 diams. 9. Sori and part of 

 leaflet of Hare's-foot Fern, magd. 5 diams. 10. Thin section of Limestone, magd. 20 diams. 



II . Group of twenty seed-vessels, natural size. 12. Group of twenty seed-vessels, magd. 6. diams. 



13. Leaflet of Polypody. 14. part of a leaflet of Hare's-foot Fern. 



