189 



The spermatozoids are very large and agree closely in their 

 development with those of Eqnisetum. 



6. The archegouium most nearly resembles that of the Marat- 

 tiaceae. Two neck canal cells may be present, and there is 

 always a division of the canal cell nucleus. A ventral canal 

 cell was demonstrated in (K pendulum. 



7. The basal wall of the embryo is probably transverse in 

 most cases, but in (J. pendulum it often varies a good deal in 

 position, probably due to the very variable position of the 

 archegoniimi. There is also a good deal of difference in the 

 degree of development of the foot, which is derived apparently 

 from the whole of the hypobasal half of the young embryo. 



8. There are three types of embryo in the Ophioglossum, 

 viz., the types ot 0. moluccanum, 0. vulgatum and 0. pendidum. 

 In the first, leaf and root only are developed. In the second, 

 root and stem, with a late development of the foliage leaf. 

 In the third, roots only. 



9. The definitive sporophyte in both 0. moluccanum and 0. 

 pendidum is formed as an adventitious bud upon the root of 

 the embryo sporophyte. 



10. In 0. moluccanum the tissues of the cotyledon and primary 

 root are continuous, and the structure of the axial vascular 

 bundle is essentially the same throughout, — collateral in the 

 leaf, monarch in the root. The primary root of 0. pendulum 

 is diarch, like the later roots. 



11. The type of embryo in (>. moluccanum is probably the 

 most primitive, and has its nearest analogy in that of the 

 Marattiaceae and Equisetum. As in these its growth is bipolar 

 and it perforates the gametophyte in much the same way. 



12. The nearest affinity of the Ophioglossum is probably with 

 the Marattiaceae, but it is probable that there is also a remote 

 affinit}^ with the Equisetineae. 



13. The presence of an endophytic fungus is universal in 

 the Ophioglossaceae, and there is no difference between the 

 form occurring in the gametophyte and in the sporophyte. In 

 the two species under consideration there is evidence that the 



