8 



The life history of the fern is divided into 

 sporophyte and gametophyte, there being two 

 distinct generations, and two types of independent 

 plants. Then compare the life history of one of 

 the higher ferns (I doubt if it ought to be among 

 the ferns proper), Selaginella. In this plant, 

 instead of spores being developed and scattered 

 as in the fern, ultimately producing the prothallus 

 or sexual generation ; the spores of Selaginella 

 are of two kinds, micro and macro spores, male and 

 female respectively. But these, instead of forming 

 an independent prothallus as in the ferns, begin 

 their development while on [the parent plant — in 

 fact the product of the megaspore, while there is 

 a trace of the prothallus, is more like the seed of 

 higher plants, as plianserogams. Again, in the 

 cyeads there is an advance, the seed of these has 

 modified more nearly to the higher types, but the 

 antherozoid or male element is still motile, but 

 only when set free from the pollan or micro- 

 spore in the ovule. In Gingko, the only surviving 

 descendant of a large order of plants in early 

 geological, Carboniferous and Permian, there is at 

 the apex of the seed a peculiar " tent pole " 

 structure, with a surrounding pollen chamber. 

 Similar structures are also seen in the modern 

 GnetacejB. Particular attention is drawn to the 

 comparative morphology of these plants. 



In Dj'. Williamson's book, he states that certain 

 fossil plants, which were at one time represented 

 to be conifers or cyeads, and at other times 

 ferns, after being bandied about by geo- 

 logical botanists for over thirty years, were 

 placed among the ferns, and throughout this long 

 period he maintained that they were ferns. Con- 

 temporary pala3o-botanists fiercely attacked, and 

 Williamson counter attacked, the idea of these 

 plants being felicina", until some specimens fell 

 into the .hands of a French palaeo - botanist, 

 Brogniart, in which the internal structure was 

 preserved, which plainly showed a layer of cam- 

 bium or growth ring in the stem. This caused 

 thesG plants again to be classed with the cyeads and 

 Ci-nifers. [A specimen of a section of one of these 

 stems was exhibited.] Williamson was still firm. 

 A little later, another Frenchman, Grand 'Eiu*y, 

 in a book written by him, stated that " Since 

 secondary growth was unknown in cryptogams 

 we are led by analogy to regard all plants so 

 organized as belonging to the gymnosperms. But 

 recently a discovery has been made of a secondary 

 growth in the stem of one of the lowest ferns, in 

 the Ophioglossuceae, Botiychium, the Moonwort." 

 This discovery settled once again, for a time, that 

 these plants were ferns, and the rest of his 

 opponents gave in. This was in 1892. 



Well preserved remains of fossil plants in the 

 coal measure series are formed generally at the 

 top, or " roof," of coal seams in coal nodules, or 

 coal balls. They vary in size, as the specimens 

 shown. Sometimes they are massed together. A 

 mass, from which a section had been cut, was 

 exhibited, and was seen to be full of plant 

 remains, generally all of one species. Fine sections 

 are made of these nodules, and examination can 

 be made under the microscope. They appear 

 much like fresh plants in Canada Balsam, except 



the staining, petrification having preserved them 

 so well. The sections showetl tangled masses of 

 foliage, raches, stipes, and other parts of hygino- 

 dendron ; glandular hairs can also be seen, and 

 these must have thickly covered many parts of 

 the plant. Transverse and longitudinal sections 

 with pith, wood, cambium, bast, inner and outer 

 cortex, the whole somewhat compressed and in- 

 filtrated in parts, branches can be seen springing 

 off here and there. In another section a root is 

 passing througli the cortical layer, and in the 

 same section a young vachis, or leaf stalk, is 

 clearly discernible. 



In another, among a mass of tangled leaf debris, 

 is a macrospore and a microspore. Both have 

 thick coats, and are much like those of Selaginella 

 mentioned before. The macrospore has thickenings 

 in the wall, with vessels. Further sections 

 showed a cone with a nearly longitudinal section 

 of a seed, and another seed in transverse section. 

 This last plainly shows the pollen chamber with 

 pollen grains in it and the " tent pole " structure 

 at the apex. 



A slide of a photo-micrograph was next 

 exhibited of an axial section of the seed of 

 Lagenostouia pkysioides, much enlarged, where 

 the *' tent pole " and pollen grains in the pollen 

 chamber are plainly seen. 



This is very like the ovule of Gingko mentioned 

 bafore. Inanotherspecimen, tugeuos^oina Lomaxii^ 

 the cupule is made tip of a series of pecidiar 

 bracts covered with glands, probably for insect 

 attraction. 



The fact of these seeds being discovered and the 

 whole plant found with them, has led to an 

 entirely new order of plants being made. They 

 go by the name Pteridosperms or " seed bearing 

 ferns," and beyond this fossil foliage of many 

 names has, owing to this discovery, found to belong 

 to many of these Pteridosperms, as for inst'ince 

 Spheiwpim-i^ ffoninijhansH is the foliage of 

 Lyginodendron (a slide of this foliage in various 

 stages of growth was shown). 



It is estimated that 8.) per cent, of the coal 

 measure "ferns" now txirn out to be pteridosperms, 

 and the principle ferns of the coal measure period 

 were of the marattiales, as angiopteri.^. 



Insects were much in evidence at the time, and 

 it is quite reasonable to' suppose a great many 

 special organs were developed in order to attract 

 them. Professor Weiss, in his paper at the 

 Leicester meeting of the British Association, on 

 ' Some Kecent Ke.:X'arches in Pollination," showed 

 this to bo the actual fact, and stated that plant* 

 in these cai-ly times were better adapted for insect 

 fertilization than mony recent flowers. 



There is much work to be done in elucidating 

 the early forms of plants, but we may have in the 

 pteridosperms a possible link with the ferns,, 

 though not from the higher, but, in all probability, 

 through the lowest group of the ferns, the Ophio- 

 glossacea.' or their common ancestor. The study 

 of fossil botany is thus rendered fascinating, and. 

 if this shcrtintrfiduction has aroused some interest 

 in this branch of the sister sciences — botany and 

 geology, it will excuse its incompleteness. 



