138 K. Miy ake, Contribut. to theFertiliz. and Embryogeny of Abies balsamea. 



reactioü do not seem to difter miich from tliose of the latter 

 (Fig. 27). Miuill (' 00) found a siniilar body in the egg- of Tsuga, 

 and stated tliat it seems to origiuate in one or more of the proteid- 

 vacuole. 



Several abnormal archegonia have been observed. Archegonia 

 mthout neck-cells have been noticed in several preparations. A 

 double archegonium, — one archegoninm Ijing above the other, — 

 was sometimes niet with. In such double archegonia the neck-cell? 

 are absent in the lower one, but the ventral canal-cell is usually 

 formed. In one case, an interesting double archegonium. as illus- 

 trated in Fig. 29, has been found. The upper archegonium lias 

 apparently two egg-nuclei, both similar in size and structure, wliile 

 the ventral canal-cell in the upper right-hand corner of the t^% does 

 not show any sign of nucleus. The Tower archegonium has a Single 

 egg -nucleus, but the ventral canal-cell with a distinct nucleus is 

 found at the side of the ^%g^ instead of at the apex. Neck-cells are 

 absent from both archegonia. Another case of an interesting monstros- 

 ity is flgured in Fig. 30. The archegonium has apparently two 

 neck parts, but ouly one of tliem has neck-cells. Two ventral caual- 

 cells and two egg-nuclei are present. 



Fertilization. 



Fertilization seems to take place three to five days after 

 the cutting oif of the ventral canal-cell. The formation of the 

 ventral canal-cell was found to take place most actively from the 

 23 rd to the 25 th of June, and the first case of fertilization was 

 observed on the 27 th, the process being apparently most active on 

 the 28 th. In my material more than half of the archegonia remained 

 nnfertilized, owing probably to the fact that many ovules were not 

 poUinated and also that many archegonia were more or less injured 

 by insects. 



When the pollen-tube reaches the ^%^, by penetrating the neck 

 of the archegonium, its apex is ruptured and nearly the whole Con- 

 tents of the lower part of the tube, including the two sperm-nuclei 

 surrounded by their common cytoplasm, the stalk-cell, and the tube- 

 nucleus, are discharged into the %g%. Fig. 41 shows a stage a little 

 before the discharge of the pollen-tube contents into the %g%. The 

 apex of the tube has already reached the t%g. and the two sperm- 

 nuclei and the stalk - cell are seen just above the dismtegrating 

 neck-cells. A dumb-bell shaped nucleus at the darkly stained apex 

 of the <dgg probably represents the nucleus of the ventral canal- 

 cell. A stage just after the entrance of the tube -contents is 

 shown in Fig. 42. Two sperm-nuclei, — one of which is represented 

 by a dotted line, — stalk-cell and tube-nucleus , are found in the 

 upper part of the ^^g. They appear as though imbedded iu, or 

 attached to the darker iinely granulär mass of protoplasm which 

 may probably represent the sperro-cyptoplasm. 



The larger of iirst sperm-nucleus soou moves down towards the 

 centre of the ^gg^ and finally conjugates with the egg -nucleus 

 (Figs. 31—33). In one case a crater-like depression was observed 

 in the upper portion of the egg -nucleus, where the sperm-nucleus 

 was Coming into contact with it. Whether this concavity is always 



