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unfertilised. Cycas itself differs from all other living seed-plants in 

 the fact that the female plant forms nothing of the nature of a 

 flower or cone ; the carpels are large, leat-like structures borne 

 directly on the main stem like the ordinary leaves. The number of 

 seeds on each carpel is often as many as six. The ripe seeds 

 may be of the size of a peach ; in Cycas revoluta the strange fructifi- 

 cation is extremely conspicuous, the scarlet seeds contrasting 

 brilliantly with the yellow carpels. 



The bearing of the seeds on little-modified leaves springing 

 from the main stem, though an arrangement unique in the recent 

 flora, was a common character among the seed-plants of Palaeozoic 

 age. In this respect Cycas is a precious relic of a past age. 



As first discovered by two Japanese botanists only fourteen 

 years ago, the mode of fertilization in the Cycads and the Maiden- 

 hair Tiee (Gzngko) is quite peculiar among living seed plants. 

 While in all the rest the male cells are passively conveyed to their 

 destination — the egg-cell — by the growth of the pollen-tube, in 

 these antique types the old Cryptogamic method prevails —the male 

 cells are capable of active movement. 



The pollen-grains are received in a chamber prepared for them 

 in the nucellus or central body of the ovule. The discovery of the 

 pollen-chamber in Cycads was made some seventy years ago by 

 our distinguished countryman, Griffith, though his work was long 

 forgotten. 



Pollen-tubes are produced, but they serve chiefly to anchor the 

 pollen-grains in the tissue of the ovule. Two sperms are usually 

 found in each tube ; they bear a number of fine protoplasmic hairs 

 or cilia, which are the organs of motion. The sperms begin to 

 revolve while still in the pollen-tube ; then it bursts and they are 

 set free ; they swim, with a rolling motion, through a drop of 

 secreted water to the egg-cell and accomplish the act of fertiliza- 

 tion. In Microcycas no less than sixteen active sperms are produced 

 in each pollen-tube, and the number of egg-cells is correspondingly 

 large. 



The great seeds of the Cycads much resemble a peach or a 

 plum, for there is a thick fleshy outer layer and a stone within ; the 

 whole thing, however, is a seed and not a fruit. 



We will now go on to the proper subject of this address, the 

 seed-plants that flourished in the forests of the Coal period. In 

 the rich flora of that time a large proportion of the plants — roughly 

 about half the entire number of species- — had the outward appear- 

 ance of ferns. Their fronds, often of great beauty of form, are 

 probably better known to the amateur than any other fossil plant- 

 remains. So close is this likeness to true ferns that scarcely 

 anyone doubted that this was their nature until a few years ago. 

 In the case of a certain fraction — and rather a small fraction — there 

 is really evidence in favour of this view ; as regards the great 

 majority, it is only lately that the question of the mode of 

 reproduction has been in any degree cleared up, and all the 

 evidence available goes to shew that these supposed ferns were in 

 reality seed-bearing plants of the same general type as the Cycads 



