lO PROCEEDINGS OF THE CANADIAN INSTITUTE. 



The first division of the o-ospore is across the long axis of the archegonium. 

 The next division is parallel with the long axis of the prothallium, and at right 

 angles to the first. The third cross wall is in the transverse direction of the pro- 

 thallium, and at right angles to the other two. I have been unable to follow 

 satisfactorily the subsequent divisions. 



The organs appear very late, and only after the embryo has attained a large size. 

 The root is the first of them to emerge, and the proliferation of cells, indicating its 

 place of origin, is long unmarked by the presence of an apical cell. The cotyledon, 

 stem apex, and foot appear nearly simultaneously. 



The root and cotyledon originate from the upper part of the embryonic mass ; 

 the foot and stem apex from its lower cells. 



The apex of the root in many cases is in the same straight line with the canal 

 of the archegonium neck. 



It seems hardly possible to derive the organs from definite octants of the 

 embryo. 



The growth of the root ruptures the calyptra, and its exit is followed somewhat 

 later by that of the cotyledon. The latter is not a bi-laterally symmetrical 

 structure, as in most ferns, but is of the same palmate type as is found in the 

 Osmundaceae. The cotyledon begins to assimilate as soon as it reaches the surface 

 of the ground, and thus resembles that of Ophioglossum pedunculosum. 



There seems to be no evidence to indicate that more than the cotyledon appears 

 above ground in the first season of the young plant's growth. In following- 

 summers apparently only a single leaf is produced, as is the case with the older 

 plant. I have found young sporophytes, bearing their sixth leaf, still attached to 

 the mother prothallium; and, as I have never found more than one leaf on the 

 spore plants at once, and as the leaves, like other organs of tfiis species of 

 Botrychium, are extremely resistant to decay, I am reasonably certain that such 

 examples were in the sixth year of their existence. This longevity of the gameto- 

 phyte is of some interest. 



One frequently finds two sporophytes oh a single prothallium, and in many of 

 these cases the apex of the prothallium is bifurcated. In one case I found two spore 

 plants which had arisen from a single embryo. In another case I discovered two 

 tracheids in a prothallium in the vicinity of a decayed young spore plant. The latter 

 .may. have been of apogamous origin, as a similar phenomenon generally accom- 

 panies apogamy. I haye not yet studied thoroughly the growing region of the 

 prothallium, as it is best examined in longitudinal sections of the gametophyte. So 

 far as I have investigated the matter, there seems to be evidence of the existence 

 of an apical cell. 



