376 BOTANICAL GAZETTE [November 



may 



very soon (fig. 23) or they may remain distinct through the sub- 

 sequent stages (fig. 24). In fig. 23 the egg apparatus fills an 



mbry 



male 



one 



becomes 



micro 



(fig. 24). These 



latter nuclei show little regularity in behavior; they may begin to 

 disorganize at any stage, but usually become more or less fused 

 before this occurs. In any event no endosperm is formed. 



The fertilized egg divides transversely to form a short filamen- 

 tous proembryo, which attains a length of three or four cells before 

 the first longitudinal division occurs. At this stage the cell toward 

 the micropyle begins to elongate and push out into the surrounding 

 placental tissue as a haustorial suspensor (figs. 25, 26). Later this 

 dies away so that the proembryo in the mature seed is a simple 

 rounded mass of cells (fig. 27). 



Corallorhiza maculata Raf. 



In Corallorhiza the embryo sac develops in a manner similar 

 to that in Phajus grandifolius, as a comparison of figs. 28-33 



20-24 



, , ~. ^ ^.^^ „ Consequently 



the above description of the sac of Phajus applies in all essential 

 points to Corallorhiza, so that a separate account of the latter is 



unnecessary 



The proembryo of Corallorhiza, as 



(6) 



ery 



micropy 



Broughtonia sanguinea R. Br. 



This species shows the same peculiarity described above for 

 Phajus and Corallorhiza. The innermost megaspore gives rise 

 to a sac with six nuclei, the primary antipodal nucleus dividing 

 only once. This division does not usually occur until the two 

 nuclei in the micropylar end divide to four, so that three spindles 

 are observed in the sac at one time. 



