186 BOTANICAL GAZETTE [SEPTEMBER 
Historical 
A summary of views in regard to the embryogeny of conifers is 
given by CoULTER and CHAMBERLAIN (10), so that it will suffice 
to note those features in the historical development of the subject 
which concern our own investigation. 
RoBERT BROWN (2), in discussing the similarities of the ovulate 
structures of cycads and conifers, mentioned his own observations 
of occasional polyembryony in conifers, which was known to be a 
constant feature in cycads. In a later treatise (3) he announced 
polyembryony as a constant feature among several genera of the 
Pinaceae and felt convinced that this feature is common to the 
entire family. He noted the origin of the embryos from ‘‘corpus- 
cula”’ or ‘“‘areolae,” 3-6 in number, at the upper extremity of the 
‘“‘aminos’’ (endosperm), and pointed out that this provision of 
several “‘corpuscula’”’ was like that in cycads, where it also made 
possible the development of several embryos. He called the sus- 
pensors “‘funiculi,”’ finding that these frequently branch to form 
still other embryos. 
MirBEL and Spacu (27) announced their results from a careful 
study of several pines and also Thuja and Taxus, confirming the 
work of Brown and extending our knowledge to other forms. In 
this account these workers were the first to use the terms ‘‘suspen- 
sor’ and “‘rosette,”’ although in their otherwise excellent figures 
they show 5 cells in each tier of the early embryo, 5 rosette cells, and 
5 vertical rows of cells coming from the base of the corpusculum. 
SCHLEIDEN (36) gave the first accurate general description of 
the development of the early embryo, beginning with the “embry- 
onal globule” on the end of the suspensor. His views regarding 
the earlier stages of the embryo were confused by his erroneous 
conception that the pollen tube formed the embryo. He pointed 
out the correct order of appearance of the stem tip meristem and 
cotyledons, and gave a good account of the formation of the sus- 
pensor in its late stages after it becomes massive, describing it as 
an elongation of cells from the radical portion of the embryo. 
Hartic (15) was possibly the first to point out that the upper 
end of the suspensor is a single cell, but he regarded this cell as 
