Some Wound Reactions in Filicinean Petioles. 
BY 
H. S. HOLDEN, M.Sc., F.L.S. 
Lecturer in Botany in the University College , Nottingham 
With Plates LXXIII and LXXIV and one Figure in the Text. 
Introduction. 
T HE healing of wounds in phanerogamic tissues is normally accom- 
plished by the production of either a callus or of a wound periderm. 
This subject has, on account of its economic value, long occupied a promi- 
nent place in botanical research, especially among experts in forestry and 
arboriculture, in whose province the question is naturally an all-important 
one. For similar reasons one finds that the occurrence of disease due to 
fungal agency has also received close attention, with the result that a con- 
siderable amount of literature has been produced bearing on these problems 
and their treatment, of which the works of Prillieux (23), Sorauer (28), 
Hartig (13), and Tubeuf (35), and more recently those of Duggar (9), 
Massee (17), and Smith (26), may be regarded as typical. In the case 
of the vascular cryptogams the investigation of wound response seems to 
have excited little interest, since any economic value is, in their case, 
absent. 
The Bonn text-book (33) says of wound response in these forms, c The 
wounded cells die, and become brown and dry, whilst the walls of the 
underlying, uninjured cells become lignified ’ (pp. 150-1) ; it also briefly 
touches upon the formation of periderm in Ophioglossttm (p. 148), a feature 
first noted by Holle (16), whose observation is also quoted by de Bary (8), 
and upon the formation of a pseudoperiderm in the Marattiaceae. 
Incidental reference to a case of periderm formation is made by Chand- 
ler (4) for Polypodium aureum , while Stopes (30) and Seward (24) also refer 
to the healing of deep wounds in Calamitean axes. 
Wound reactions of a somewhat different character are recorded by 
Strasburger (32), who describes the formation of tyloses in the carinal 
canals of Equiseta when the upper portions have been cut away, and by 
[Annals ol Botany, Vol XXVI. No. CHI. July, 1912. J 
