The Development of the Egg and Ferti- 
lization in Pinus Strobus. 
BY 
MARGARET C. FERGUSON. 
With Plates XXIII, XXIV, and XXV. 
URING the course of the present studies, the develop- 
ment of the archegonium and fertilization, together with 
the phenomena immediately preceding and following fecunda- 
tion, were first carefully worked out in Pinus Strobus. Later, 
a far less extended study was made of Pinus austriaca , P. 
rigida, P. resinosa , and P. montana , var. uncinata . A com- 
plete series of stages in the development of these species was 
not obtained, and, therefore, the conclusions as set forth in 
this paper refer, unless otherwise stated, to Pinus Strobus , the 
other species being used only by way of comparison. The 
methods employed in the preparation of the material for this 
research were fully described in my earlier paper (’01) and 
need not be repeated here. 
These investigations were begun, at the suggestion of 
Prof. George F. Atkinson, in the fall of 1897, and the prin- 
cipal results of the work, as herein described, were read before 
the Botanical Society of America at its Boston meeting in 
1898. At this time Blackmans (’ 98 ) excellent article, 
* Fertilization and Related Phenomena in Pinus sylvestris,' had 
[Annals of Botany, Vol. XV. No. LIX. September, 1901.] 
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