LINNEAN SOCIETY OF LONDON. 55 



and strongly heats the trunk, but not svifficiently to affect its 

 vitality, a flower-bud is formed in the centre of the uninjured 

 bud, and the following spring and summer witnesses the almost 

 uniform production of the gigantic floral spike by all the older 

 plants so affected, while those missed by the fire remain barren. 

 Were all other signs of the fire absent, the flowering and non- 

 flowering Grrass-trees would fairly well indicate the boundary of 

 the fire. 



The increase in height and dimensions of the Kangaroo-Island 

 Grasri-trees seems to bo very slow. Old settlers intimate with the 

 aspect of particularly remarkable individuals assert that they 

 could discern but little change in from twenty to thirty years. 

 If this be correct, many of the larger ones may exceed a hundred 

 years of age, and some of the oldest may have seen several cen- 

 turies pass. In that case the branches would indicate excep- 

 tionally severe disturbances of the vegetative life, and the remains 

 of flowei'-stalks seasons of bush-fires and other smaller accidents. 

 It is to be regretted that the wonderful plants are totally unpro- 

 tected, and that the larger ones are year by year becoming fewer. 



The most remarkable structural feature is the presence of a 

 ligneous " core " immediately above the roots ; universally present 

 in X. Tateana and rare in A'^, quadrangulata, it appears to be 

 absent from the other species of the genus. The core is conical, 

 as hard as maliogany, the largest obtained being 13 X 7f inches, 

 and, in the author's opinion, the structure approximates to exo- 

 genous growth. 



Soral Apospory on Polystichum angulare var. pulcherrimum, 

 Moly. By C. T. Dkuert, F.L.S. 



[Read 21st February, 1889.] 



In sundry papers which were read before the Linnean Society 

 as the results of investigations made from 1884- to 1886, a series 

 which culminated in Prof. F. 0. Bower's monograph of Dec. 16, 

 1886, "On Apospory and allied Phenomena," detailed records 

 were given of the discovery of a faculty' of aposporous reproduc- 

 tion in abnormal varieties of two distinct species of Ferns, viz. in 

 Atlujrium Filix-fcemina var. clarissima and Polysticlium angulare 

 var. 2'>ulcherrimum, Padley ; and on the last-named date I reported 

 a third instance, which I had recently observed upon another 

 form of P. angulare, also of tlje 2)i(Ic/ierriviHm-ty\ie, but found 

 by Dr. Wills in Dorsetshire some 80 miles distant froni Mr. 

 Padley's discovery. 



The forms of apospory in Athyriiim and Folgsticliiim difler very 

 essentially, the phenomenon being confined in the first case to the 

 sorus, whore the sporangia became abortive at an early stage and 

 prothalli developed from their stalks ; in Polystichum, however, 

 either the extreme tips of the pinnules ran out into slender pro- 



