Hodowla przedrośli paproci w warunkach pracowni szkolnej na przykładzie narecznicy samczej - Dryopteris Filix-Mas (L.) Schott

Abstract

When the question of metagenesis in fern is examined during botany lesssons in school it is highly recommendable, if only for methodological reasons, to demanstrate a gametophyte. The best and most certain way to obtain mature prothalia is to cultivate them on the spot. There are different ways of cultivation, on different kinds of subsoil. Our experiment haye shown that the vegetable mould is a highly adequate subsoil. In Fig. 1 we have presented a diagram of a culture ot this type. During the growth of this experimental culture the development of the prothalia of Dryopteris Filix-Mas has been carefully observed (Figs. 3-13). Upon mature prothalia, with developed archegonia and antheridia, live spermatozoids were observed, and their positive chemotaxis to malic acid was studied. Finally, a prescription has been made - and presented in the paper - how to make lasting preperations with mature prothalia and young sporophyte stages, preserving the green colouring. The method consists in drying up the prothalia upon microscopic slides to the dessicated-air stage, and then in closing them up in Canada balsam.