324 Scientific Proceedings, Royal Dublin Society. 



that the two male cells are formed in the grain just as the pollen tube begins 

 In Pseudotsuga, as in others, the body cell divides far down in the pollen 

 tube. The details, then, of fertilization need completion, though the process 

 is obviously similar to that in the other Abietineans. 



The embryo is formed in the typical fashion, with division of the fusion 



nucleus into four, their passage to the archegonial base, further division 



into 8 with wall formation, and so on. Though all the stages were noted, 



PI. XVIII, figs. 11, 12, 13, are sufficient to add Larix to the list of those 



genei'a already shown to have embryo development of the Abietinean type. 



It is hardly likely that any important variation will appear in the others, not 



yet demonstrated. In spite of that, such demonstration is much to be 



desired. As against Pinus, only one embryo is usually formed from one 



fertilization, although on one occasion two embryos were found attached to 



the one suspensor. Embryonal cells or secondary suspensors were developed. 



The archegonial base was gradually compacted at the attachment of primary 



suspensor and rosette to form a deeply staining mass very similar to the 



" plug" described by Lawson. It was not determined if this were merely a 



temporary compacting of the archegonial cytoplasm or a mucilage plug as 



distinct as in Pseudotsuga. 



All stages up to wall formation at the 8 nuclei stage were found on 

 June 15th. The other stages up to PI. XVIII, fig. 12, were found on 

 June 23rd, although the stage figured was by far the most common. The 

 fig. 13 was from July 7th, and the rest of that month saw the gradual 

 organization of the great body regions. By mid-August the embryo was 

 mature and the cycle complete. 



III. — The Position of Lakix. 



There is one main result appearing from the facts recorded from the study 

 of Larix leptolepis, and that is a definite placing of it in its natural systematic 

 position. A study of its stem anatomy had already indicated what 

 that position was ; but the few new facts here recorded have clearly 

 fixed it. 



The natural position of Larix has suffered much at the hands of the syste- 

 matists. Strasburger (24), in a genealogical tree at the end of his " Coniferen 

 und Gnetaceen," puts together Larix, Pscudolarix, and Ccdrus. In Schumann's 

 Lehrbuch (22) Larix and Cedrus are linked with Pinus near, while Picea and 

 Abies are linked as distinct from the others. Warming (29) puts together 

 Picea, Larix, Cedrus, and Pinus, and includes Tsuga and Pseudotsuga together 

 as sub-genera of Abies. Von Wettstein (30) (the recent 1911 edition was not 



