1908] KILDAHL—PHYLLOCLADUS ALPINUS 343 



The second integument, called an arillus, arises quite late outside 

 of the heavy integument; on November 1 it appears merely as a small 

 papilla in longitudinal section (fig. 75). It grows very rapidly, 

 inclosing the ovule like a cup; the ovule, however, grows up through 

 it, and by December n it is merely a light, leathery sheath around 

 the base of the ovule, reaching about half-way to its tip (fig. 14). 



Female gametophyte 



It was impossible from the material in hand to ascertain the 

 development of the female gametophyte, as the formation of walls 

 was in most cases well advanced on November 1. In a few instances 

 it was still in the free nuclear stage (fig. 18); and one preparation 

 showed archegonia already formed. The endosperm is of the " rumi- 

 nating" type, this feature being especially pronounced in the early 

 stages. 



The development of archegonia could not be observed, as no stage 

 before fertilization was available. It is impossible, therefore, to state 

 definitely whether neck cells are formed or not. Some indefinite 

 remains of cells, in a few sections, indicate that they exist; and com- 

 paring Phyllocladus with the Taxineae, and taking into consideration 

 that neck cells are often destroyed very early by the pushing-in of the 

 pollen tube or the growth of the central cell, the probability is that a 

 two-celled neck exists in the early stages of the archegonium (fig. 32b), 

 although nothing was found upon which a definite statement can be 

 based. In Torreya taxi folia Coulter and Land (9) found two neck 

 cells; Arnoldi (i) also found two in Cephalotaxus Fortunei; Jager 

 (13) reports two in Taxus baccata. From such a condition as that 

 shown in figs, ig, 31, 32, it may be inferred that the presence or absence 

 of neck cells would make very little difference. The whole structure 

 of nucellus and gametophyte is of a very mucilaginous composition, 

 and this, together with the prodigality of pollen tubes and male cells, 

 presents a very loose and disintegrated condition. The archegonium 

 in every case, whether located near the surface of the gametophyte or 

 deeper in the tissue, presents an opening as large as the width of the 

 sac. The pollen tube penetrates the tissue, digesting it very readily, 

 and seems to break through the layer of jacket cells surrounding the 

 embryo sac as though no obstacle were in its way. No instance was 



