134 BOTANICAL GAZETTE {FEBRUARY 
depth ( fig. 29). The edges of the cotyledons are very close 
together, so that the plumule is almost inclosed in a tube. The 
opening just above the plumule is conical as in Podophyllum. 
The plumule is slightly more developed here than in Podophyllum 
or Jeffersonia, but consists simply of a mound of tissue. The 
hypocotyl is longer in relation to the size of the entire embryo 
than in either of these forms. 
SUMMARY. 
1. In each of the three plants studied the embryo is small, 
surrounded by a large amount of endosperm richly stored with 
starch. 
2. In each case the cotyledonar primordium isa broad, ridge- 
like structure open at one side. This ridge later bifurcates oppo- 
site the opening to form two lobes, the cotyledons. The two 
notches soon become of almost equal depth, so that older stages 
do not give a correct impression of the origin of the cotyledons. 
3. 48 Podophyllum a long cotyledonar tube is formed, and in 
Caulophyllum the edges of the cotyledons are close together. 
The plumule of Jeffersonia is not inclosed in either way. 
4. The plumule is not. well developed in. any of these 
embryos, but has a central origin in each. 
THEORETICAL CONSIDERATIONS. 
There are among the angiosperms certain plants which show 
peculiarities either in their vegetative structure, their embryol- 
ogy,orin both. Some of these plants have flowers of very sim- 
ple form, and certain botanists believe that in them we have 
primitive characters, and that the comparative study of a large 
number of these forms may reveal much concerning the origin 
of the structures found in more highly developed plants. 
Others hold that the simple forms represent merely a derived 
condition, and that their peculiarities are not of the highest value 
in determining relations, but have been acquired as an adapta- 
tion to the conditions under which the plant has developed. All 
agree that it is important to investigate the development of these 
plants, because it is only by the accumulation of a large number 
of facts that we have a basis for definite and reliable conclusions- 
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