342 BOTANICAL GAZETTE [November 



When the two male cells are equal, it is commonly inferred that 

 both function. So far as could be determined, only one male cell 

 functions in Phyllocladus, and the second male cell, together with the 

 other three nuclei discharged into the egg cell from the pollen tube, 

 disintegrate as the proembryo develops, as shown in fig. 26. Arnoldi 

 (1) finds in Cephalotaxus that the second male cell remains in the 

 upper end of the egg and later goes through a mitotic division. 



The Taxineae are equally divided in regard to the size of the 

 male cells. In Torreya taxijolia they are unequal (Coulter and 

 Land 9) ; they are also reported unequal in Taxus by Belajeff (3), 

 and by Jager (13) ; Arnoldi reports them of the same size in Ceph- 

 alotaxus (1); and they are equal in Phyllocladus. Outside of the 

 Taxineae they are equal in Juniperus communis (Noren 17), Thuja 

 (Land 15), Sequoia (Arnoldi 2), Pinus Banksiana (Coulter ii), 

 and Pinus Laricio (Chamberlain 6). Miss Ferguson (12) finds 

 them unequal in Pinus Strobus; and one functioning male cell is 

 reported in Podocarpus by Coker (7). Land (13) finds in Ephedra 

 trijurca that the male cells are equal, both enter the egg, but only one 

 functions. 



Ovulate strobilus 



The ovulate strobilus occurs on the side of the phylloclad (in the 

 axil of a scale leaf) near its base (fig. 12). It usually occurs singlys 

 but frequently in pairs; never more than one pair was seen upon a 

 single phylloclad. The strobilus consists of six to eight rather fleshy 

 scales, each scale bearing a single ovule in its axis. 



The ovule has two integuments, entirely free from the nucellu, 

 to the very base. The inner one is very thick and consists of three 

 layers : an inner fleshy, a middle stony, and an outer fleshy consisting 

 of only two layers of cells. The stony layer begins to develop at the 

 micropylar end and extends toward the base. At first it consists of 

 only one layer of cells, but later it becomes much thicker and extends 

 all the way around the base of the ovule, where, however, it remains 

 much thinner than at the micropylar end. The inner fleshy layer 

 is somewhat crowded out by the growth of the stony layer; and the 

 outer fleshy layer is finally sloughed off. The integument contains no 

 vascular strands; these end at the base of the ovule {fig. 15); it con- 

 tains a number of resin ducts, shown in the cross-section in fig. 16. 



