Pink: CON'TRIBUTIOX TO THE LIFE-IIISTOKY OF RUMEX. 1-47 



is not the usual relation during fusion of these nuclei. The 

 conditions existing in Fig. 28 are somewhat of an enigma, 't'he 

 sac is surely larger than it could be previous to fecundation, but 

 the two smaller nuclei in the anterior end look like those of the 

 synergidae. Also the definitive nucleus lies near the egg as I 

 uniformly find it in Rumex vcrticillatus before fecundation. I 

 thought for a time that I had here a pollen tube showing one 

 sperm nucleus within and the other discharged and entering 

 the egg. However, taking into account the appearance of the 

 two smaller nuclei and the restful condition of the egg, I have 

 concluded that the sac is one whose ^^g failed to be fertilized 

 and in which one synergid has disintegrated leaving its nucleus 

 while the other is rapidly dwindling. If this is true, the sac 

 has gone on increasing in size the same as if the Q.<g^ had been 

 fecundated. The next stage observed after that already ex- 

 plained (Fig. 26) is that represented in Fig. 30, in which the 

 tube had discharged, the first two endosperm nuclei had divided 

 and the spindles were persisting, and the egg was evidently 

 preparing to divide. A little later phase was also found (Fig. 

 29), in which the tube was persisting and showed the broken 

 end beautifully, the egg was dividing and three of a probable four 

 endosperm nuclei were visible. The tube frequently persists in 

 both plants till the sporophyte is well established (Fig. 35), and 

 in one instance an undischarged tube was seen in the sac of 

 Rumex verticillatus after the embryo was well established and 

 four endosperm nuclei were dividing (Fig. 34). This tube, 

 containing two sperm nuclei, is a second one which entered the 

 sac after fecundation had been accomplished. 



An exhaustive study of the embryo will not be attempted ; but 

 I shall state a few observed facts concerning its origin and early 

 development, making no use of the terms suspensor and pro- 

 embryo, but designating the structure from the beginning as the 

 embryo. The first division then of the embr3^o occurs soon 

 after the egg has elongated and secreted a cellulose wall about 

 its base to attach it to the anterior end of the sac and is trans- 

 verse (Fig. 29). The second and third divisions were also 

 transverse in several instances observed (Fig. 35), and the 

 fourth was a longitudinal division of the distal cell of the em- 

 bryo (Fig. 31). In an instance observed the third division was 

 transverse and closely followed by a longitudinal dividing the 

 second cell from the distal end (Fig. 32). During its early de- 



