. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. 40 MORPHOLOGY OF SPERMATOPHYTES regarded the two ovules as representing a single flower. In 1890 Celakovsky ^ published the view that the stalk is an axil- lary shoot bearing two or more carpels, but that each carpel is represented only by an ovule. This means that the presence of the carpel is purely theoretical. The same author â¢'â * in 1900 reaffirms this position with greater fullness of detail. In 1896 Fujii/^ after a study of abundant Japanese material, and espe- cially taking into account numerous abn
. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. 40 MORPHOLOGY OF SPERMATOPHYTES regarded the two ovules as representing a single flower. In 1890 Celakovsky ^ published the view that the stalk is an axil- lary shoot bearing two or more carpels, but that each carpel is represented only by an ovule. This means that the presence of the carpel is purely theoretical. The same author â¢'â * in 1900 reaffirms this position with greater fullness of detail. In 1896 Fujii/^ after a study of abundant Japanese material, and espe- cially taking into account numerous abnormal developments, came to the conclusion that the stalk is a shoot, usually bearing two rudimentary carpels. That the ovules are really related to carpels appears from the fact that he found them upon more or less modified foliage leaves. In other cases he found transition stages be- tween the normal collar and blades bearing ovules, his con- clusion being that the collar represents the rudimentary carpel. The short stalk which is sometimes quite evident in connection with each ovule stands, therefore, for the peti- ole of a megasporophyll. That the main stalk is a shoot was further evidenced by the fact that cases were found in which a stalk bore several ovules and terminated in a scaly bud. The results of Seward and Gowan's ^^ studies coincide with the views of Fujii. These observers have still further strengthened the position by the record of additional abnormalities. A summary of what seems to be the most reason-able view of the homologies of the ovulate structures in Ginkgo is as follows: The main stalk represents a shoot bearing two or more carpels, and these carpels mostly occur in rudimentary form, the petiole being represented by the short stalk upon which each ovule stands, and the blade by the so-called collar. The development of the megasporangium seems to be al-. FiG. 81.âGinkgo biloha, longitudinal sec- tion of ovule: i^ integument; w, mi- oropyle; p, bealc
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