HE Mu "butions to the Euh ane y of the Amentiferge: —Part II. Carpinus Betulus. 
By MancanET BENSÓN, D.Sc., F.L.S., Senior Lecturer in Botany at the Royal 
Holloway College, Toha ELIZABETH SANDAY, B.Sc.; and Emity BERRIDGE, 
B Se, F.L.S. 
(Plate 6.) 
Read 16th November, 1905. 
INTRODUCTION. 
P ART I. of these contributions was read before the Linnean Society on the 15th of 
June, 1893, and included the first instalment of results obtained by one of us. The full 
details relating to Carpinus were not given in that paper, nor has any work since been 
published by other investigators on the embryology of this most interesting genus. 
In the spring of 1902, therefore, two of us determined to undertake its investigation, 
especially as Nawaschin’s brilliant discovery of triple fusion in the embryo-sac of Lilium 
suggested the inquiry whether a similar process took place in chalazogamic forms, and 
if so, in what way it was carried out. 
Nawaschin’s work on Betula (1) and on Corylus (2) was published before the 
discovery of double fertilization. We thus had no work on these genera carried out in 
the light of this recently obtained knowledge. 
METHODS. 
From an extensive series of sections prepared in 1902-3, combined with a series 
of confirmatory preparations from material secured in 1904, numbering in all about, 
600 slides, we have been able to trace the complete history of the embryo-sac and its 
nuclei from the entrance of the pollen-tube to the first segmentation of the egg. The 
material was collected chiefly from trees growing in the grounds of the Royal Holloway 
College. 
The first gathering was made at 12 noon on Friday, July 4th, and this was repeated 
every day, as far as possible at various times, until July 17th. 
Both in 1902 and 1904 the fertilization processes seem to have been occurring chiefly 
between the dates July 6th and July 10th. 
Three different solutions were used for fixing :— 
1. Absolute alcohol. 
2. Flemming’s solution (strong formula). 
3. 2 » (weak formula). 
The ovaries were dissected immediately on gathermg, the ovary-wall being removed 
as far as possible, so as fully to expose the ovules to tlie action of the fixing agent. 
SECOND SERIES.—BOTANY, VOL. VII. I 
