. The structure and development of mosses and ferns (Archegoniatae). much augmented during the past ten years. Jef-frey (i) has described very fully the gametophyte of Botry-chiiim Virginiamim, and Lang (4) and Bruchmann (5) havemade out the most important facts in that of Ophioglossum andHelminthostachys. Our earlier knowledge was based entirelyupon the fragmentary observations of Hofmeister (i) uponBotrychmm lunaria, and those of Mettenius (2) upon Ophio-glossum pediinciilosum. The writer has succeeded in securing the earliest phases ofgermination in two species, viz., Ophioglossum (Ophio-de
. The structure and development of mosses and ferns (Archegoniatae). much augmented during the past ten years. Jef-frey (i) has described very fully the gametophyte of Botry-chiiim Virginiamim, and Lang (4) and Bruchmann (5) havemade out the most important facts in that of Ophioglossum andHelminthostachys. Our earlier knowledge was based entirelyupon the fragmentary observations of Hofmeister (i) uponBotrychmm lunaria, and those of Mettenius (2) upon Ophio-glossum pediinciilosum. The writer has succeeded in securing the earliest phases ofgermination in two species, viz., Ophioglossum (Ophio-dernia) pendulum and Botrychium Virginianum, as well as theolder prothallia of the latter. The germination in both casesis extremely slow, especially in the former, where a year and ahalf after the spores were sown the largest prothallia had butthree cells. Probably under natural conditions the growth ismore rapid. The spores of both forms show much the samestructure. The tetrahedral spores contain granular matter, VII PTERIDOPHYTA—FILICINEAl—OPHIOGLOSSACEJE 235. with numerous oil-drops, and a central lar,e^e and distinctnucleus. The exospore is colcjurless, and upon the outsidepresents a pitted appearance in Ophioglossuni, and irrej:^u]arsmall tuhercles in Botrycliiiini. The jicrinium or epis])ore is notclearly distinguishable from the exospore. in both caseschlorophyll is absent in the ripe spore. The first sign of ger-mination is the absorption of water and splitting of the exosporealong the three radiating lines en the ventral surface of thespore. The spore enlarges considerably before any divisionsoccur, but remains globular in form, and nochlorophyll can be detected. In this con-dition, which was observed within twoweeks after the spores were sown in Ophio-glossnm, it may remain for several monthsunchanged. The first division wall isusually at right angles to the axis of thespore, and divides it into two nearly equalcells, of which the lower has more of thegranular cont
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