PESTS AND PABA.SITES. 



19 



been attacked and half demolished, also some other of the 

 Boss Terns, especially the Crisped Boss Eernand the Broad 

 Boss Tern, the latter the last to be attacked. They also 

 commenced on the Eoyal Ferns, and had entirely destroyed 

 one or two fronds before they were observed. Morning 

 by morning the lady and her servant went and took some- 

 times from twenty-five to thirty off one plant. When the 

 Lady Ferns, Boss Ferns, and Royal Ferns fail, the depre- 

 dators would prey upon the Shield Ferns, but only when 

 they could get nothing more tender. 



"Woodlice and kindred Crustacea are also sometimes 

 great pests among ferns. The surest way of checking 

 their marauding expeditions is to ofi'er them something 

 which they like better. If, for instance, potatoes are cut 

 in half, and a portion scooped out from the centre of the 

 flat side, and these cups are inverted in localities fre- 

 quented by the woodlice, they will collect in the cavity, 

 and whenever the potatoes are examined a goodly number 

 may be secured. Carrots have also been recommended 

 as equally efficacious. 



Vegetable parasites are not much annoyance to the 

 cultivator, since they chiefly confine themselves to plants 

 in the uncultivated state, or when the fronds are dead. 

 Moulds occasionally appear on the young ferns grown 

 from spores, but these generally proceed from the soil or 

 peat on which the seeds have been sown. The Brittle 

 Bladder Fern is subject to have the under surface of the 

 fronds sprinkled with orange-coloured patches, caused by 

 an orange powder which bursts through the cuticle. This 

 is a parasitic fungus,^ and the orange powder its seeds or 

 spores. Although only found on this fern in Britain, it 

 has been detected on other species abroad. 



The under surface of the fronds of the common Bracken 

 sometimes present a curious appearance from short par- 

 allel black lines, which at first resemble clusters of spore- 

 cases in their arrangement, but difi'ering in colour as well 

 as position, for the parallel lines of spore-cases observed 



* Uredo filictm. 



