316 ■ Transactions. 



rainfall had changed but little, there is to-day an almost entire lack of 

 those taller and denser timber areas which were the home of the majority 

 of the more delicate species of Hymenophjllum and Trwhomanes, and I 

 venture to suggest that the humidity within those areas that remain is 

 also lower than it formerly was. For instance, in December, 1916, the 

 stream that usually flowed through Le Bon's Bush, though never of large 

 dimensions, had actually dried up, and the forest-floor could scarcely have 

 been described as damp ; yet there are evidences that this piece of forest 

 was particularly rich both in wealth of fern-growth and in number of 

 species. 



To the wholesale destruction of the bush that accompanied the cutting- 

 out of the timber and the conversion of these areas into pasture the 

 disappearance or partial disappearance of many ferns is undoubtedly due, 

 as, e.g., Gleichenia Cunninghamii and Pteris tremula, both of which appear 

 to have been abundant. Then, again, where cattle have had access to 

 the bush the undergrowth, with its wealth of terrestrial ferns, has dis- 

 appeared save for a few hardy species that, seem able to accommodate 

 themselves verv rapidly to new and harsher conditions, as, e.g., Asplenmm 

 bulbiferum, Pellaea rotundifolia, Polystichum Richardi, P. vestitum, Blechnum 

 lanceolatum, B. fluviatUe, B. discolor. 



Most of the larger Hymenophylla seem to have disappeared entirely, 

 though the smaller species may still be found. The reason for this I am 

 unable to state. It has to be remembered, however, that the favourite 

 haunts for these ferns were the valleys between Le Bon's Bay and Damon's 

 Bay, and that the bush has been practically cleared away from these areas. 

 Further, it seems more than probable that these ferns cannot endure wind, 

 which now blows freely through bush where formerly the air was perpetually 

 still. 



On the coastal rocks the following ferns are much less common than 

 they apparently were formerly : viz., Gymnogramme leptophylla, G. nitae- 

 folia, Blechnum. Banksii, Asplenium Richardi. In fact, no trace of either 

 Gymnogramme was seen by me. Other ferns commonly met with on banks 

 and slopes immediately above high-water mark seem to hold their own 

 against such aggressive exotics as Dactylis glomerata, Agrostis stolonifera, &c., 

 while the pastures have been invaded by Blechnum penna marimmi. This 

 fern must, in the district under consideration, have descended from its 

 former subalpine station right down to sea-level, where it is now. common 

 in places from which in the past it seems to have been absent. The 

 two species" of Gymnogramfne formerly grew on steep banks of partially 

 decomposed rock, where introduced grasses havei now obtained a footing, 



and this may, wholly or partially, explain their disappearance. 



» 



Summary of the Results op the Investigation. 



It will be seen from the following lists that at least seven (possibly 

 eight) of the twenty species inquiretulae mentioned by Laing are still grow- 

 ing in the district investigated, while Riches has shown that fourteen at 

 least were former inhabitants. Of the sixteen species excludendae four 

 were present — viz., Hymenophyllum scahrum, Hymenophyllum ferrugineum,, 

 Trichomanes humile, Trichomanes Colensoi. 



Riches informs me that a considerable patch of a small-leafed umbrella- 

 fern {Gleichenia dicarpa 1) formerly grew near the summit of the hills at 

 the head of O'Kain's, while he has specimens of Lindsaya linearis Swartz 

 and Lindsaya cuneata Forst. var. Lessonii Hook. f. collected somewhere in 



