Show Life History of a Fern By Jessie W. W Hoopes FERNS comprise a large group of crypto to amic plants forming in a wide sense a very naturally limited group though they constitute by far the greater number number number num num- ber of the They were 1 especially characteristic of the carboniferous erous age and it seems as though they were more widely distributed and grew much larger than they do at the present time The life-history life of all these is divisible 1 into two distinct stages or genera generations 1 in which not only are the external characteristics extremely different but the physiological functions are also j 1 sharply contrasted The older botanists starting from the study of flowering plants endeavored to 1 recognize in all other cases the same characteristic points of structure They did not doubt therefore arguing from 1 analogy that tha ferns were provided from frum true see seeds s. s Gerarde 1597 observing ii i i the appearance of young plants in the neighborhood of old ones attributed it to the dissemination of seeds II for for I believe said he II all all plants have seeds in themselves to produce their kinds No Noone one however at this time could say anything definite about th the seeds of ferns and they came to be regarded as highly mysterious W. W Cole appears to have been the first to microscopically observe the spores pores themselves 1669 But Morison 1715 seems to have been the first to put the matter to the test of actual experiment He sowed the spores and in due course without however distinguishing clearly the two stages raised plants from them This important important important tant observation fell completely into oblivion and when in 1789 Dr Lindsay responding to a request of Sir Joseph Banks for fern plants to be sent from Jamaica by suggesting that spores could be much more conveniently sent the latter was quite unprepared for the suggestion suggestion suggestion sug sug- which he treated as a great dis dis- covery Dr Lindsay accordingly wrote a paper on the subject in which he figured the stages of the plant The spores of ferns were still however regarded as equivalent to seeds i. i e. e as the result of a process of fertilization similar to that which precedes precedes precedes pre pre- cedes the development of seeds in flowering flowering flowering flower flower- ing plants A variety of attempts were made to see in hairs or glands upon the young leaves something that would answer answer answer an an- for an anther and even as late as 1832 De maintained the analogy of the pro thallium to a cotyledon In 1844 the final step was reached when found upon the the archegonia shaped flask-shaped bodied containing a central cell which when fertilized by the anthero- anthero develop into a spore-bearing spore plant similar to that from which the the- cycle started The vigorous vigorous' s' s vegetative ferns which are what are familiarly ur understood der tood when i ferns are spoken of are only one phase of their life They are the and the reproductive bodies bodies' they bear spores germinate without any process of fertilization and are therefore not to be compared with seeds The same thing is equally true of the theother theother theother other members of the series viz horse tails club mosses etc A spore or germination produces a structure which compared with its immediate immediate immediate im im- mediate parent is relatively very small and bears no resemblance to to- it in form and texture I It t is called the lium Hum it is green and membranous and attached to the surface of the ground by small root hairs in ferns and horse tails in adder tongues and club mosses it is tuberous and subterranean while in still others it always remains more or less included within the cavity of the parent spore The function of the is entirely reproductive it develops sexual organs of two kinds archegonia and antheridia either upon the same or different There are many plants which like mammals birds and other highly organized organized organized or or- animals reproduce themselves exclusively in the se sexual ual way because in the normal course of life at least no other mode of reproduction is open to them these comprise those which have been mentioned in the earlier part of this essay the majority of the conifers and also many flowering plants such as palms flax hemp etc The great majority of plants however have abundant opportunity of multiplying and reproducing themselves otherwise than by means of sexual organs It I t is only here necessary for me to mention the potato which has for hundreds of years continually been propagated by its tubers and thus by the the sexual mode There are in fact many and plants which have in the course of time either ent entirely rely lost their sexual organs or have let t them em become functionless but which nevertheless r multiply and propagate themselves The consideration of this fact which i. i could easily be shown by numerous other examples leads to the question What is F the precise object which Nature attains by the production of sexual organs and by sexual propagation This question i appears more pertinent when we see on the other hand with what care Nature proceeds in very many cases to ensure the union of the sexual cells and the production of sexually produced de de- It is well-known well by all botanists that the highest development of the organization is always attained only by means of fertilization In the thet t case of ferns this is at once obvious on remembering that the first generation produced from the sexual spore the is usually a minute very k simple structure the life and importance of which are closed with the fertilization of the whereas the embryo x originating from this act of fertilization xe a develops into a highly organized plant a tree-fern tree for instance De Bary however discovered cases of ferns which give rise to new fern plants directly from the tissue of the by means of budding In two of these forms no archegonia whatever whatever what what- ever r are developed on the although antheridia occur occasionally In some instances of these forms on the theother theother f r other hand there are found completely devoid of sexual organs and still capable of propagation by means of 7 budding as well as others with a few antheridia and finally which bear antheridia and archegonia but nevertheless give rise to the fern by simple budding All facts considered there can be no doubt whatever even in inthe inthe inthe the case of these ferns which seem to have lost the sexual organs that the pro pro- thallia formerly gave rise to normal f sexual organs and propagated themselves f in the ordinary way and the loss of sexuality was only as physicians say acquired through long cultivation The fern plant plan t as we know it is really nothing but the the originating from the egg cell and containing containing containing con con- minute spores which germinate and form pr thallia on which are borne the true organs of reproduction These are born on the under surface of the leaf and near the center The leaves are for forthe forthe forthe the most part ovate-oblong ovate to oblong- oblong linear and veined Those upon which the true organs of reproduction tion are born seem to roll upon them them- selves This is probably for the protection protection protection tion of the delicate spores By observing closely it is found that the under surfaces of these leaves are moist and that the antheridia seem to have the power of moving along through this moisture and by so doing fertilizes the archegonia These spores germinate and take root and as the little plant becomes larger the dies leaving it attached to the ground as an independent f dent den t plant plan t. t |