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CASSELL'S POPULAE GARDENINO. 



compelled to employ spores in their propagation, as 

 division and bud-producing fronds afiord ready 

 means for their increase. Many Ferns are, of course, 

 abundantly fertile, Gymnogrammas, Pteris, some 

 Adiantums, CheilantheB, Aotinopteris, and numerous 

 others being weU-known examples. But, on the 

 other hand, it has been hitherto impossible to obtain 

 plants from the spores of such Ferns as Trichomanes, 

 HymenophyUum, Davallia, many Poljrpodiums, Glei- 

 chenias, &c. We must suppose that sterility in these 

 eases is the probable result of artificial cultivation ; 

 for the wide area over "which the above plants are 

 distributed in nature can only be explained by their 

 spores being fertile. Sometimes we find spores pro- 

 ducing prothallia, but not getting beyond that stage ; 

 from which we must infer that the functions of fer- 

 tilisation have been weakened by some cause or other, 

 although the spore itself is produced, and from it the 

 prothallus is expanded, but without the capacity to 

 produce plants. This may be considered as analo- 

 gous to what we see in many cultivated flowering 

 plants, the flowers of which are developed, but all 

 efforts to make them produce fruits proving of no 

 avail. Whether the sterile nature of the Filmy 

 Ferns has caused them to assume a proliferous cha- 

 racter in their foliage cannot perhaps be proved, but 

 we flnd that many of the HymenophyUums and Tri- 

 chomanes, whdn grown under glasses, are proliferous 

 to an extraordinary degree in their old barren 

 fronds. It is possible that the failure on the part of 

 the prothallia to produce plants may be due to un- 

 favourable conditions as regards light, heat, or some 

 other circumstance, and that therefore a change of 

 treatment might prove successful. We have tried 

 many different kinds of spores in many different 

 ways, hut, except those of known fertility, little or 

 no success has been met with, although strong, 

 healthy prothallia have sometimes been obtained. We 

 have not succeeded in raising plants from the spores of 

 Lycopodium, SelagineUa, and Psilotum, though they 

 have been tried under various conditions. Perfect — 

 i.e., fertile — spores retain their vitality for a long 

 time acccording to various authorities ; we have not 

 tested them beyond the age of twelve months, hut, 

 jonless it be for exportation, spores are not likely to 

 be wanted to keep longer than a year. They should 

 be kept dry and warm, as the smallest seeds of tro- 

 pical plants, such aa .Gloxineas, are preserved. In 

 gathering spores it is best to select those leaves, or 

 portions of leaves, on which the spore-cases are not 

 quite ripe ; if left to get ripe the spores are often 

 lost, as the cases generally open as soon as ripe and 

 eject their spores. Shake the fronds after they have 

 been gathered, so as to remove if possible all foreign 

 spores that may have settled upon them whilst in 

 the house. Place them in sheets of smooth paper in 



a perfectly dry place. In a few days the spore-cases 

 win have burst, and the spores will be found scat- 

 tered over the paper. 



In preparing pots for the reception of the spores, it 

 wUl be well to bear in mind that both in the soil and 

 in the atmosphere in or near a Fernery myriads of 

 spores are scattered ; and these, if allowed to get into 

 the pots along with the sown spores, not unf requently 

 vegetate first, and are either mistaken for the desired 

 plants, or usurp the conditions supplied for them, so 

 that these are either prevented from growing, or lost 

 through being crowded. For spores of choice Ferns 

 the following plan is in use at Kew : — Pots, usually 

 four-inch, are crocked and filled with soil, the latter 

 consisting of peat with fine crocks mixed amongst it, 

 and sometimes a little sand. These pots are placed 

 in large flat pans, generally large enough to hold five 

 pots of the above size, and to allow a large bell-glass 

 to fit inside and rest on the bottom of the pan. The 

 pots being filled and Eirranged in the pans, boiling 

 water is poured over soil, pots, and pan in quantity 

 sufficient to make the whole quite hot. The bell- 

 glass is then placed over the pots, and the whole is 

 allowed to stand till the soU. has again become cool. 

 To sow the spores, the pan, &c., are carried into a 

 shed away from the houses, the hell-glass is taken off 

 only long enough to allow of the scattering of the 

 spores over the soil and labelling each kind, and is 

 then replaced and tied on to the pan. Water is 

 poured into the pan, and this prevents the air from 

 getting into the soil, as well as keeping the whole 

 moist, so as to obviate the removal of the bell-glass. 

 If properly managed it should be easy to destroy or 

 keep out all germs from the soil on which the spores 

 are sown, so that the first signs of vegetation under 

 the glass should be those of the sown spores. Some 

 Pern-spores germinate rapidly and vigorously, and 

 for these it is not necessary to take all the trouble 

 described above. A pot of peat soil, well watered 

 before sowing the spores, and a pane of glass over 

 the top, affords such kinds all the conditions they 

 require. The temperature most suited for spore- 

 raising depends on the nature of the Fern, but as a 

 rule a temperature of from 70° to 75° should suit 

 all but the coolest kinds, which may be placed in a 

 temperature 10" lower. The spores should be shaded 

 from bright light. As soon as the prothallia are well 

 advanced, should they be crowded it will be neces- 

 sary to transplant them into pots of well-drained 

 peaty soil, separating the mass of prothallia into 

 little patches of the size of a threepenny-piece, and 

 carefully planting them about an inch apart all over 

 the soU. The finest soU should be used, and, should 

 the Ferns be delicate kinds, it will be well to mix a 

 quantity of finely-sifted crocks along with the peat. 

 In filling the pots with soil the middle should be 



