6 
H. MARSHALL WARD. 
embryo-sac nucleus in Gymnadeniareinains uncertain from my 
drawings. According to Slrasburger, the typical process is as 
follows — The fourth nucleus from the group in the anterior 
end of embryo-sac travels down, and meets one of the four 
from the posterior end, and, fusing together, these two form 
one large nucleus — the nucleus of the embryo-sac. The 
three nuclei left behind are ‘‘ antipodal cells or Gegen- 
fusslerinnen.” This process I have failed to observe 
directly in Gymnadenia, but may remark in this connection 
upon figs. 14, 15, 16, and 17, in each of which are indica- 
tions possibly of some such process. 
In the first case (fig. 14), we have an ill-defined mass of 
protoplasm in the posterior end of the sac, and two large 
well-rounded nuclei close by the egg-cell above though 
the bare possibility exists that one of these nuclei is on the 
adjacent wall of an integument cell, since the case is not 
isolated, yet it is offered here. In fig. 15 we have a large 
bright nucleus below, and a faintly marked (badly preserved?) 
body on the side wall of the sac. In fig. 16, both above and 
below, appear good round nuclei. In fig. 17 the upper 
nucleus has evidently travelled down, and now abuts upon 
the mass of protoplasm at the base of the sac ; this mass is 
well rounded, and presents four nuclei, or, more correctly, 
two large nuclei, in a comm.encing stage of division. 
Were it not for the fact that in Strasburger’s drawings 
and description this process is so definitely put, and also that 
in other cases (esp. Ranunculus, Lobelia, Anthericum, 
Butomus, and Alisma),® I have often seen two nuclei free 
in the sac besides the antipodal cells and a normal egg appa- 
ratus, the above evidence would not deserve to be so insisted 
upon ; it is incomplete, and is little bettered by the sugges- 
tion that in these highly specialised plants a process of 
reduction has become still more reduced, and that even the 
rudiments are unusually imperfect and uncertain. However 
this may he, in Gymnadenia conopsea there are formed a 
normal “ egg- apparatus,” a large nucleus of the embryo-sac, 
and a group of “ antipodal cells.” 
The pollen- tubes should now be somewhere in the neigh- 
bourhood, and in fig. 17 we have an example showing the 
^ ‘ Ueber Befruchlung u. Zelltheilung/ p. .32, Orchia pa liens ^ Com- 
pare Vesque’sdiflerent account of Orchis galatea, ‘Ann. des Sc. Nat.,’ 1878. 
^ Is it possible tliat this is a case of two egg-cells? Strasburger figures 
two embryos in the same sac, in a paper published in Jen. Zeitschr. f. Wiss., 
1878 — “ Ueber Polyernbryonie.” 
^ In Butomus there can now be no doubt of the fusion of two nuclei. 
I have every stage in the process. Sec a paper read before Linnsean Society, 
Nov. 20th, 1879. 
