24 The American Naturalist. [January, 
ance and to the great development of the sporophyte. In CEdo- 
gonium the egg divided into four swarm-spores. For one sexual 
act four plants may be obtained. In Chara the number of spores 
produced directly from the egg is still greater, and the carpogone 
wall becomes thickened and specialized as a covering to protect 
the result of the sexual act. In Riccia the egg itself develops 
an epidermal layer, besides the spore-mother-cells within. As the 
number of these spores becomes greater a columella is required 
to strengthen the capsule; it appears inthe Anthocerote. To 
scatter the spores better the capsule is elevated on a stalk in the 
Jungermanniz. To the same end elaters are developed in the 
Hepatic (and later in the Equisetacez). The stalk of the cap- 
sule becomes longer and the whole sporophyte more complex in 
the Musci. In the ferns, leaves and roots are assumed by the 
sporophyte, in order that (having access to more nutriment) it may 
produce more spores. Throughout the whole upward series of — 
developing, specializing, progressing sporophytes we see one dis- 
tinct end in view, viz., the making of an egg, when fertilized, go 
` as far as possible. 
Now whether there is any difference between the sporophyte — 
a 
developed, under these conditions, in an aquatic plant like Chara 
or Coleochzte, and the sporophyte developed under exactly simi- 
lar conditions in an amphibious plant like Ophioglossum, I can- — 
not say. Certainly in either case the meaning of the sporophyte — 
remains the same. It is, wherever we meet it, whether in Chara — 
or in Juglans, in CEdogonium or Taxus, a device for making the : 
most out of that sexual act accomplished with so much difficulty, 
and with the chances so tremendously against successful com — 
summation. 
If the correct explanation of the origin of sporophytes is givet 
above, it is difficult to see why a sporophyte should not in every 
case be considered an “ interpolation ” between successive gameto- < 
phytes. Wherever met, the sporophyte is simply more or less 
elaborate subdivision of the fertilized egg. In Œdogonium it is 
a direct subdivision; in Helianthus it is an indirect subdivision. — 
Properly speaking, the gametophyte is the p/ant ; the sporophyte | 
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