Ii6 
JOHN T. BUCHHOLZ 
Pinus edule, Pinus ponder osa, Pinus Sabiniana, Picea excelsa, Larix 
europaea and Pseudotsuga taxifolia. It is in the upper axils of these spirally 
arranged simple leaves that the first needle-bearing branches appear toward 
the close of the first season's growth, and the older branches have the homo- 
logues of these simple leaves in the form of scales that likewise subtend the 
spur shoots. 
Discussion 
The cotyledon primordia frequently fuse in Pinus Banksiana and Cedrus 
Lihani, and this fact is so evident that it is not open to question, for here 
the process of fusion, when it occurs, is prolonged into the early stages of 
cotyledon elongation. The situation in Picea and Larix is not so simple, 
because the fusions of the primordia occur more suddenly, before the cotyle- 
dons elongate, making it necessary to employ the statistical method. 
The appearance of a larger number of primordia than cotyledons is 
apparently a recapitulation of a feature in the phylogeny of the conifers, 
and since the examples chosen for study were selected from several different 
genera of the Abietineae, it indicates that the fusion tendency is quite 
general in this group. Occasionally the process expresses itself in other 
ways than by fusions, for a primordium sometimes becomes aborted In 
Cedrus Lihani. It should be remembered that though some species failed 
to show fusions, no ontogenetic evidence of a splitting of cotyledons has 
been found in any species. 
Recapitulation in external anatomy has long been recognized in the 
seedling stages of the conifers, such as Thuja, Phyllocladus, Ginkgo, etc. 
Jeffrey, in his recent work (8), cites numerous internal anatomical features 
which show recapitulation in the seedling stages. It is, therefore, not sur- 
prising that recapitulation should be found in the stages of the embryo 
before the seeds are shed. When the embryos are still enclosed within the 
seeds they are affected far less by the external conditions which bring about 
diversity. The writer has also demonstrated instances of recapitulation in 
the early embryos of the pine by finding that an apical cell of the pterido- 
phyte type persists until an embryo mass of several hundred cells has been 
formed. Recapitulation has therefore been found in stages earlier as well 
as later than this cotyledon stage, and it is only to be expected that the 
cotyledon primordia should be found to show well marked tendencies to 
fuse if this is the manner in which dicotyledony has arisen. 
The number of cotyledons in many species of gymnosperms is quite 
variable, and this variation has had a tendency to obscure any evidences of 
recapitulation. A fact which is significant in this connection is the well 
recognized tendency for a primitive or genetic form to show varying char- 
acters. A famiHar illustration of this is shown in the number of petals, 
stamens, or carpels found in the Ranunculaceae, which belong to one of the 
lowest orders of the Archichlamydeae. Here the flower parts are spiral or 
