SCHIZAEACEAE 547 
Probably they had originally a more complex annulus than those of the 
present day. 
The development of the sporangium follows in its main features the 
usual Fern-type, each being referable to a single parent-cell, with rectangular 
base. It is specially noted by Prantl,! that in all the Schizaeaceae the 
first segment-wall extends from the outer to the inner periclinal wall of 
this cell: such segmentation is a feature characteristic of the more robust 
types of Fern-sporangium (Fig. 305). This is followed by two other anticlinal 
divisions, as seen in section, and then comes the 
périclinal division which separates the cap-cell from Kon, 
the archesporium. The former gives rise to the AY 
greater part of the sporangial wall, while the lower YY | 
segments complete the wall, and form the short 
stalk. In the archesporium the usual tapetum and 
sporogenous group are formed: the latter consists, 
however, of a larger number-of spore-mother-cells Poe borne zie Eee 
‘ : : 3; the first t wall 
than usual in the Leptosporangiate Ferns: in theets’ the periclinal (basal) 
Aneimia Prantl figures 16 spore-mother-cells as seen Ye ron Carey ete the 
from one side only of the sporogenous mass, and fh ban" fthe eer aad 
I have seen the same number in AZoAéria actually 
traversed in a single section. These observations led to an enumeration 
of the spores actually produced from the sporangia of the Schizaeaceae: 
in Lygodium japonicum and dichotomum the number approximated to 256, 
but in ZL. prnnatifidum to only 128: there is thus a difference between 
species of the genus, as in Zodea and elsewhere. The lower figure is 
shared also by Schizaea,2 Mohria and Aneimia. The numbers are thus 
larger than are seen in ordinary Leptosporangiate Ferns, and they approach 
those seen in the Osmundaceae. The largest number is seen in Lygodium : 
it will be seen that its anatomical characters also mark this genus out as 
more archaic in structure than the rest of the family. 
Fic. 305. 
ANATOMY. 
The Schizaeaceae show diversity of habit, varying from those with 
creeping rhizome and laxly disposed leaves to those with ascending or 
upright stock, and leaves densely spiral: the internal structure of the 
shoot also shows marked differences, which follow these differences of 
habit.2 In Zygod/um the simplest vascular structure is found, for there 
the rhizome is traversed by a protostele with solid xylem consisting of 
tracheides and parenchyma, surrounded by phloem, pericycle, and 
endodermis. There is no typical proto-xylem: the first formed tracheides 
1Z.e, pe 49. 2Tansley and Chick, Azz. of Bot., 1903, p. 495- 
3See Boodle, Az. of Bot., 1901, p. 359, and 1903, p. 511; Jeffrey, Phd. Trans., 
B, 1902, p. 128; also Tansley and Chick, Azz. of Bot., 1903, p. 493- 
