130 MORPHOLOaY OP SPEEMATOPHYTES 



minal pore. Each male cell fuses with a free egg, and as many 

 oospores are formed as there are male cells discharged into the 

 sac — that is, twice as many as there are discharging pollen 

 tubes (Fig. 91, /). The oospore was observed to organize at 

 once about the fusion nucleus a comparatively dense layer of 

 cytoplasm, and soon a cell membrane appeared. The oospores 

 may remain free, or they may become attached to the tips of the 

 pollen tubes which belong to them. 



IV. THE EMBEYO 



Ephedra. — An account of the development of the embryo of 

 Ephedra altissima is given by Strasburger.* Germination be- 

 gins with free nuclear division, and two to eight free cells, some- 

 times more, are organized within the oospore (Fig. 89, B). 

 These free cells do not organize any definite tissue as in Coni- 

 fers. As a consequence, each cell continues to act independ- 

 ently, elongating to form a suspensorlike tube, which emerges 

 from the oospore and penetrates the endosperm (Fig. 89, C). 

 The more or less numerous tubes, emerging in various direc- 

 tions, are bulbous within the oospore, where they are in contact 

 with its nutritive supply, and at the free tip cut off a single cell, 

 from which the embryo proper is developed. The embryonal 

 cell divides transversely, which is followed by other transverse 

 divisions, forming a short filament (Fig. 89, D, E). Longitudinal 

 divisions succeed, and later periclinal divisions (Fig. 89, i^). jSTo 

 details of the organization of the growing points are recorded. 



Turnboa. — After fertilization, it is reported that the arche- 

 gonium initial elongates and penetrates the endosperm as a 

 suspensor, which is a long, much-coiled, and very persistent 

 structure, and carries the egg in its tip. It is probably the fact 

 that the so-called archegonial suspensor is a tube developed by 

 the oospore, just as in the free oospores of Gnetuin, and that the 

 so-called egg in its tip is the nucleus of the oospore. In any 

 event, the embryonal cell appears as a small cell cut off at the 

 tip of the suspensorlike tube (Fig. 90), and gives rise not onlv to 

 the embryo proper but also to numerous embryonal tubes 

 *• (Fig. 92). 



According to Bower's account "' '^ of the embryo, the first 

 division of the embryonal cell is longitudinal. Then a trans- 



