t914] MANEVAL—MAGNOLIACEAE 5 
They appear simultaneously and are independent from the start, 
there being no evidence of a pseudo-monocotyledonous habit such 
as occurs in various other members of the Ranales. In the mature 
seed the embryo is typically dicotyledonous, with a short radicle 
and well developed hypocotyl and cotyledons (fig. 37). 
The seed coats of Magnolia have been described by different 
botanists, probably the earliest correct description being that given 
by Asa GRAY (10). In the mature seed the outer integument is 
differentiated into two layers, an outer fleshy one well filled with 
oil receptacles, and an inner stony layer of bony hardness. The 
inner integument forms only a thin layer in the ripe seed. After 
dehiscence of the carpels the seeds remain suspended a few days 
by means of an elastic thread formed from the spiral thickening 
bands of the xylem elements of the raphe. Finally the threads 
may be broken and the seeds fall to the ground; or sometimes the 
entire cones with most of the seeds still attached are shed. This 
shedding of the cones results from a break across the base of the 
peduncle, but without the formation of a definite absciss layer. 
In the case of Liriodendron the development of the endosperm 
and embryo were not investigated. 
Before discussing the embryo sac and certain other points 
mentioned above, several features of gross structure and anatomy 
deserve attention. ARBER and PARKIN (2) define the term flower 
as ‘‘a special form of a type of strobilus common to angiosperms 
and certain mesozoic plants,” and propose to designate it as an 
anthostrobilus. The anthostrobilus differs from all other strobili 
in that it is typically amphisporangiate, with the megasporophylls 
above the microsporophylls on an elongated axis, and below the 
sporophylls a distinct perianth which is wholly or partially pro- 
tective. The angiospermous type of anthostrobilus is called a 
euanthostrobilus, and is believed by them primitively to have 
possessed among others the following characteristics: a large or 
indefinite number of parts arranged spirally; ovules orthotropous, 
several in each ovary, with two integuments; marginal placenta- 
tion; filaments short, bearing long anthers with the connectives 
prolonged beyond them; members of the perianth all similar, 
or more or less differentiated; entomophilous. The flowers of 
