BOTANY the number of species of lichens and Uredineje has been doubled since the publication of the lists of cryptogamic plants, compiled by Mr. B. Daydon Jackson, which appeared in Pryor's F/ora, for these two groups the greater part of the county is altogether unexplored. On the other hand it is not likely that the Pteridophytes will be added to, nor that any great accession will be made to the Bryophytes. THE FERNS (Filices) While man has in past times altered the scenery and flora of the county by clearing the forests and draining the land, perhaps one of the greatest pleasures of a stroll along our country lanes has been lost to us during the present generation by the almost total eradication of the ferns which were fairly plentiful and of varied species in our younger days. Some years ago they were uprooted and taken to London from the woods and lanes of southern Hertfordshire in cartloads, but they are now so scarce that this depredation has ceased to be profitable. There is a lane near St. Albans in which not many years ago some half-dozen species were flourishing, but the bracken is the only one now to be found there. This is not due to the rapacity of botanical collectors, but to the wholesale removal of our ferns for the London market, thence to be planted in London gardens, carry on a sickly existence for a few years or maybe only a few months, wither and die. Neither in its soil nor in its climate, however, is Hertfordshire a county in which ferns would naturally flourish, both the soil and the air being too dry for them, and the rainfall insufficient and too intermittent. Not a single species is recorded from every one of our botanical districts, there being no record in the Cam district even for the very common bracken (Pteris aquilina)^ which indeed is of very rare occur- rence on the Chalk downs. The hart's-tongue (Scolopendrium vu/gare) and the common polypody (Polypodium vu/gare) are the only other ferns recorded for every district but the Cam, in which we have alone on record the male-fern (Lastrea jilix-mas) and the adder's-tongue (Opbio- glossum vulgatum) ; and in the Thame and the Brent the only recorded occurrences are of the three commoner ferns first named. Our rarest species are Pilularia globulifera^ found in a pond at Nor- thaw in the Lea district, Lastrea spinulosa and L. oreopteris, recorded only for the Colne and Lea districts, and Ceterach officinarum, which, although rarer than those two, has occurred in the Ivel district as well as in the Colne and Lea. A single specimen of Cystopte ris fragilis has been found in Berry Grove Wood, Aldenham, and a single specimen of Phegopteris calcarea at Broxbournebury, but we cannot consider these to be native ferns. They must have been casuals or escapes. The following is a list of the Hertfordshire ferns POLYPODIACE^ Scolopendrium vulgare, Sm. Pteris aquilina, L. Asplenium ruta-muraria, L. Blechnum spicant, Roth trichomanes, L. Ceterach officinarum, Willd. adiantum-nigrum, L. 61
