Transactions. 23 



the sporangia are covered by a thin membranous layer called the 

 indusiitm. The presence or absence of this covering, as well as 

 its shape, forms a distinguishing characteristic for several different 

 species. We see in the polypody it is wanting, in the male fern 

 it is kidney-shaped and attached at the side, in the lady fern 

 [Athyrium Jilix fcemina) it is kidney-shaped and fringed, while in 

 the shield fern it is circular and attached in the centre. Mr 

 Wilson next described experiments which he made in propagating 

 ferns from the spores, and exhibited numerous microscopic draw- 

 ings of the spores during their development into the leafy expan- 

 sion or prothallium. This prothallium, he said, does not develop 

 into the true fern, but it bears on its under surface the organs of 

 reproduction, viz. : — antheridium and archegonium ; these he 

 described, and traced the embryo fern until the young fronds were 

 fully developed. The result of his experience was that it takes 

 aliout four to six months before the prothallium is developed, and 

 twelve months more before the young fronds are fully formed. 

 The length of time, however, depending on the age of the spores. 

 The method of pi-opagation which I have just described is 

 called the natural one, and if you will allow nie, I shall briefly 

 introduce to you another, which may lie called the artificial. 

 Some species of ferns possess peculiar vital properties, and although 

 they can be propagated from spores, they may also be by cuttings. 

 If a portion of the stipes of the common hart's-tongue be cut off 

 so as to retain a piece of the caudex and planted in eaith, covered 

 with glass, or placed in the dark, and kept warm and moist, it 

 springs up into a fully developed fern. If a portion of a vigorous 

 growing frond of the Filix Lastrea or Polystichum Angulare be 

 taken and the pirniae cut off close to the rachis on the one side, 

 and placed under similar conditions as the hart's-tongue, young 

 ferns spring up at the base of the other pinnte. There is one 

 species, Campyloims flexuosuf^, which carries a young plant on the 

 tip of its frond, and two others, Asplcnium Bulhifcrum and 

 Asplenium viviperum, which bear a number of plants on their 

 fronds. I have growing in this flower-pot four young ferns which 

 were taken from the fronds of the paront Asplenlum bulbi/eriim in 

 June last. It was supposed that these were produced by the ripe 

 spores remaining in the sporangia, and on their being moistened 

 they developed into the young ferns, as is the case with some 

 tropical plants. Without questioning the accuracy of this state- 



