Doyle — Observations on the Morphology of Larix teptotepis. 321 



the tube, or from the stigmatic hairs. Now Strasburger (25) had earlier 

 described the pollen grain of Larix curopea as germinating, like the grains 

 of other conifers, on the nucellus, so the following observations may be of 

 interest: — It was found that all through late spring grains were to be seen 

 in the upper micropylar chamber, but none were seen on the nucellus, not 

 even in collections as late as June 9th, though grains were found frequently 

 in Lhe upper chamber. It is not, however, contended that there were 

 absolutely no grains on any nucellus during this period. It is possible that 

 if a larger number of ovules had been fixed and cut, a few examples of grains 

 on the nucellus might have been found ; but actually in those cut from the 

 late spring collections none were found on the nucellus tip. Conditions 

 were different, however, in the case of the collections of June 15th. In 

 about one ovule in every five the nucellus was supplied with one single grain, 

 with its pollen-tube mature, and fertilization already effected. In two ovules 

 only were there two grains on the nucellus. So that Strasburger's observation 

 for Larix curopea is verified by this observation for Larix leptolepis. 



We can therefore definitely state that Larix has a micropylar pollen- 

 receiving device essentially similar to that of Pseudotsuga; but that, while 

 the grains of the latter genus can germinate in the micropylar tube in mid-air, 

 as it were, it appears that the pollen grains of Larix cannot so germinate, 

 and only those grains which, by means at present not clear, are able to reach 

 the nucellus can proceed to further growth. That there is some hindrance 

 to their falling on the nucellus would appear from the paucity of grains found 

 germinating, usually only one in any ovule. 



Finally, it is tempting to look on this as a reduction from Pseudotsuga ; 

 nay, further, to assume with Burlingame (1) that perhaps the pollen-tube 

 development and pollination of Araucaria are primitive in the conifer phylum, 

 and so to present Araucaria, Pseudotsuga,, Larix, and Picea as a series in the 

 reduction of the pollen tube and the passage of the grain from the cone scale 

 to the nucellus. 



Female Gametophyte and Embryo. 



As one would expect most of the stages in Gametophyte and Embryo 

 development in Larix to be similar to those of other Abietineae already 

 described, only such points will be fully dealt with as are peculiar to Larix 

 or are of other special interest. 



The first stage found was the megaspore itself. The tetrad formations 

 have been described for Larix curopea (26) and Larix sibirica (14), the former 

 with only three cells in the linear tetrad, the latter with four. The remains 



