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types on the whole strange and unfamiliar. The plants of those days 

 do not readily admit of comparison with the better known families 

 of the present-day flora. During what follows I shall have to 

 make constant reference to a small group of living plants, the 

 Cycadaceae, or *' Cycads," for short, which in many respects stand 

 the nearest to the early seed-plants and give the best clue to their 

 interpretation. As this family may not be familiar to all my 

 hearers, it will be worth while to give a short sketch of this group, 

 so as to render the allied fossil forms more intelligible. One or two 

 Cycads are met with not uncommonly in cultivation ; thanks to the 

 kindness of Dr. Ord and Mr. Sherring, I have on the platform a 

 beautiful living example of Cycas revolnta, which may well serve as 

 a type. 



Those who wish to extend their knowledge of the family have 

 only to go to Kew, where a magnificent collection of these plants 

 forms one of the glories of the Royal Gardens. 



The Cycads are widely distributed in the tropical and sub- 

 tropical regions of both the Old and New Worlds, though seldom 

 abundant. There are nine genera: one, the type-genus, Cycas, is 

 common to Asia and Australia ; two, Macrozamia and Bowenia, are 

 Australian ; two, Stangeria and Encephalartos, South African ; while 

 four, Zamia, Ceratoza?nia, Dwon, and Microcycas, are American, the 

 last-named being peculiar, so far as we know, to the Island of Cuba. 

 This Cycad is inappropriately named, for the American botanist, 

 Caldwell, who has re-discovered the plant on its native hills, finds 

 it to be a tree 30 feet high, with female cones a yard long. A few 

 species of Cycas are said to grow still taller, but most Cycads have 

 comparatively short, though often massive and long-lived stems. 

 Some of the South African specimens in the palm house at Kew 

 are more than a hundred years old. 



The ordinary form of leaf is pinnate, bearing a deceptive 

 resemblance to many leaves of palms, with which the family has 

 nothing to do. Sometimes quite peculiar forms of leaf are met 

 with, as in a Cycas discovered a few years ago in Assam, in which 

 the scattered leaflets are repeatedly forked. The African Stangeria 

 has foliage so like that of a fern that it was actually described by 

 competent botanists as a fern, until the cones appeared and showed 

 its true nature. This is a really interesting resemblance, because it 

 points to a relationship, as the fossil evidence shows. In some 

 Cycads the way the leaves or leaflets are coiled in the bud is 

 another fern-like character. 



In recent Cycads the sexes are always distinct, and the' male 

 plants always bear their fructification in the form of cones, often of 

 very large size. Each scale of the cone is a stamen, but very 

 unlike the stamen of a flowering plant. The under-side of the scale 

 is covered with a multitude of pollen-sacs, like the sporangia on the 

 frond of a fern. 



In eight out of the nine genera the female fructification is also 

 a cone, resembling the male in external appearance, but more 

 robust. Each scale bears on its margin two ovules, sometimes 

 brightly coloured, which may grow as large as a plum, even though 



