564 Gibbs . — On the Development of the 
A complex of proembryos with suspensors forms a cavity at the apex of 
the prothallus. One suspensor develops an embryo which penetrates the 
central cylinder. Starch formation is initiated in the central cylinder cells 
immediately below the embryo, and mitotic divisions occur in the cells. 
The two divisions must follow one another in rapid succession, as four 
daughter nuclei are generally seen enclosed in the same limiting membrane. 
These nuclei further divide up to eight, remaining active and normal even 
when the cells are packed with starch. 
The cavity formed by the complex gradually closes up as the embryo 
increases in size. Resin canals surround the plerome cylinder before the 
cotyledons are differentiated, and appear in their tissue as soon as the latter 
develop. 
In the mature embryo the root-cap extrudes through the apex of 
the prothallus. 
The cortical tissues of the embryo are packed with starch, but none is 
seen in the cells of the plerome cylinder. 
The structure of the hypocotyl is that of a diarch root, and has two 
areas of primary bast alternating with two poles of the protoxylem, showing 
spiral vessels. Two branches from each pole pass to each cotyledon. 
Resin canals are present in the root-cap, hypocotyl, and pith of the 
mature embryo. 
The acquisition of a considerable quantity of material in various young 
stages has rendered it possible for the first time to bring forward a certain 
amount of evidence in favour of the view that in Podocarpus we are dealing 
with a much modified cone. The cone character is well seen at an early 
stage, but subsequent developments, including the swelling of the bract 
bases at the expense of the lamina, or the shedding of the latter and the 
great development of the ovuliferous scale, together with the reduction in 
the number of fertile members (usually only one), completely mask the 
strobilus organization. This view was formulated by Bennett and Brown ( 2 ) 
as early as 1838 , and later by Sperk (50) and Bertrand (3), and quite recently 
by Tison (57), working on Saxegothaea. With the exception of Tison 
these authors were limited to herbarium material. 
In conclusion, my thanks are due in New Zealand to Mr. T. F. Cheese- 
man, Curator of the Auckland Museum, for most useful data on localities 
and seasonal developments, and also for the inestimable aid rendered by his 
admirable ‘ Manual of the New Zealand Flora’ ; to Mr. F. Grey, of Nelson, 
for his indefatigable kindness in arranging expeditions in that district, of 
which his steady botanical exploration has given him an unrivalled 
knowledge ; and to Professor Charles Chilton, of Christchurch, for his kindness 
in allowing me to avail myself of laboratory facilities at the University to 
test material obtained. 
