238 STRUCTURE AND LIFE HISTORIES 
or gametophytic generation. In other words they have 
the same value as spores, and the one-celled stage of the 
spermagonia and oogonia the same value as spore-mother- 
cells. 
220. Female Gametophyte. Each of the four cells re- 
sulting from the reduction-divisions in the oogonial 
protoplast divides again, producing a total of eight cells, 
which constitute a simplified gametophyte. No further 
divisions occur in the oogonia. In some of the Fucaceae 
(e.g., Fucus vesiculosus) each of these eight daughter-cells 
functions as a female gamete or egg; but in Ascophyllum, 
and a few other species, part of the daughter-cells, as 
stated above, disintegrate or abort, leaving only from one 
to five. In Ascophyllum nodosum one-half of them abort, 
leaving only four eggs. The female gametophyte is thus 
seen to be reduced to merely its gametes. 
221. Male Gametophyte. Each of the four cells 
resulting from the reduction-divisions of the spermagonial 
protoplast undergoes four divisions in succession, re- 
sulting in 64 cells or a total of 256, all of which develop 
into a male gamete, or sperm. The four daughter-cells, 
therefore represent a very greatly reduced male gameto- 
phyte. 
222. Simplification of the Gametophytes. The im- 
portant point to note in connection with the life history of 
Ascophyllum is, not only the great simplification of the 
gametophyte, but the fact that it is reduced to nothing 
but fertile or reproductive cells. Each of the four spores 
gives rise only to gametes; no sterile cells, or gametophytic 
plant bodies are produced. 
223. Gametophyte or Sporophyte. In light of the facts 
above related, the question as to the real nature of the 
