FRUCTIFICATION OF FERNS. 



379 



if these be watched "with sufficient attention, the rupture of some 

 of the Thecse and the dispersion of the Spores may be observed 

 to take place whilst the specimen is under observation in the field 

 of the Microscope. In Sori whose capsules have all burst, the 

 Annuli connecting their two halves are the most conspicuous 

 objects, looking, when a strong light is thrown upon them, like 

 strongly-banded worms of a bright brown hue. This is particu- 

 larly the case in Scohpendrum, whose elongated Sori are remark- 

 ably beautiful objects for the Microscope in all their stages ; until 

 quite mature, however, they need to be brought into view by 

 turning back the two Indusial folds that cover them. The com- 

 monest Ferns, iDdeed, which are found in almost every hedge, 

 furnish objects of no less beauty than those yielded by the rarest 

 exotics ; and it is in every respect a most valuable training to the 

 young, to teach them how much there may be found to interest, 

 when looked for with intelligent eyes, even in the most familiar, 

 and therefore disregarded, specimens of Nature's handiwork. 

 280. The Spores (Fig. 193, a) set free by the bursting of the 



Fig. 193. 



Development of Prothalliiim of Pteris serruMa .-— a, Spore set 

 free from the theca ; — b, Spore beginning to germinate, putting 

 forth the tubular prolongation a from the principal cell b ;—c, 

 first-formed linear series of cells;— r», Prothallium taking the 

 form of a leaf -like expansion ; a first, and b second radical fibre ; 

 c, d, the two lobes, and e the indentation between them ; /, f, 

 first-formed part of the Prothallium ; g, external coat of the 

 original Spore ; h, h, Antheridia. 



