ABNORMAX, FERNS, 



ABNOEMAL FEENS.* 



BY E. J. LOWE, ESQ., F.R.S. 



Tlie reproiluction of ferns from spores is a studj^ of much interest, 

 and one worthy of more general attention. The modus operandi is 

 fraught with dithcnlties. The minute size of the infant ferns in their first 

 growth is in itself dangerous, as any neglect will at once destroy the 

 whole crop. The spores germinate as mere green points, imperceptible 

 at first to the unassisted eye, and only rendered visible by the look of 

 greenness from a number springing into life together. Spores of ferns differ 

 fi"om seeds of plants, inasmuch as they have no special organs ; consisting 

 merely of a homogeneous cellular mass. In seeds the young roots and the 

 young shoots are pi-esent in the embryo, being developed from deter- 

 minate points ; whilst spores, on the contrary, consist merely of single 

 vegetable cells, growing indifferently from any part of the surface. 



These points of life, (germinal fronds,) as they continue to grow have 

 a sti'ong resemblance to Liverwort, (hence the term Marchantia-like.) 

 They gradually increase in size, and, if they do not become impregnated, 

 will occasionally exceed half an inch in diameter. 



The impregnation of the germinal frond does not seem to be capable 

 of being accomplished without the action of strong light ; indeed, grown 

 in a somewhat daik corner the growth seems to be arrested before 

 arriving at that particular stage of life. The following experiment will 

 illustrate what is meant : — Three years ago a large Wardian case was 

 prepared, and the siirface of the soil scattered over with spores from a 

 number of varieties of Scolopendrium vuUjare, Lastrea flix-mas, 

 AtJti/riitm fiHx-fa;mina, Foh/.tticlium anguhire, and of Lastrea dilatata ; 

 each species being in a separate partition. This case was placed in a 

 somewhat dark corner, under a plant stage. When the spores had been 

 sown about six months the whole surface soil was covered over (and had 

 been for several weeks previously) with the vivid green of the young 

 ferns. At this time a second case was prepared, not for spore sowing, 

 but for transplanting, in patches, the germinal fronds from the first case. 

 Small portions of this green mass were lifted on the point of a knife and 

 planted in thick lines. The second case was then placed in a light 

 part of a greenhouse, having a north aspect. Under these circumstances 

 the transplanted patches very soon grew rapidly, (whilst those in the 

 case from which they were taken had made little or no progress,) and in 

 six months the second case was filled with a mass of fronds, yet no fronds 

 appeared in the original case. A third case was then prepared, and for 

 the second time small portions were removed from the first case into the 

 new one, and this also was placed in a well-lighted situation, having a 

 north aspect. After being in this third case less than six months a large 

 number of fronds appeared, whilst still no fronds appeared in the original 

 case. A fourth case is now about to be planted froin the same original 

 stock, which, although still looking green and healthy, has no fi-onds 

 developed, and, indeed, the germinal fronds it contains are still little 

 more than mere points. Thus, for three years the growing spores in a 

 darkened corner have remained all but dormant, whilst those trans- 

 planted from it have, in a situation of stronger light, a forest of fronds, 

 varying between one inch and six inches in length, according as they 

 have been selected from the second or third cases. This is mentioned as 

 a very curious fact. 



* Read before the Biological Section of the BirminRham Natural History 

 and Microscoi)ical Society, December 11th, 1877. 



