598 
Notes. 
Filicineae. 
Homosporous Leptosporangiates. 
Celakovsk/s view here maintained that poriferous segment of pinnule , 
bearing as a rule sporangia on its lower (dorsal) surface, is the homo- 
logue of the outer integument of the ovule in Angiosperms, and indu- 
sium that of the inner integument. Evolutionary series can be traced 
beginning with — ( i) Thyrsopteris 2ca<\Hymenophyllaceae y where indusium, 
enclosing sorus, is terminal to leaf-segment = most primitive type. (2) 
Dicksonia , Cibotium , Davallia , Lygodium : the indusium, along with 
sorus, is displaced on to lower surface by outgrowth of leaf-segment. 
(3) Cysiopteris, Cyaihea , &c. : sorus arises from earliest stage onward 
on lower surface. (4) Polypodium , Pteris cretica : indusium com- 
pletely disappeared; all these conditions have their homologues in 
stages of the proliferated ovule. 
Heterosporous Leptosporangiates. 
In Salviniaceae the fruit is equivalent to an ovule with one integument; 
indusium = inner integument, and leaf-lobe bearing sorus is probably 
homologous with outer integument. Striking resemblance between 
monangic sorus of Azolla and an ovule. In Marsiliaceae fruit = com- 
pound fruit of Salviniaceae. In Pilularia it is homologous with the 
pinnately 4-foliolate leaf of Marsilia ; in Marsilia with a pinnately 
multifoliolate leaf. Outer wall of sporocarp is homologous with upper 
surface of outer integument of ovule ; indusium, enclosing many sori y 
with inner integument of latter. 
In most Filicineae sorus is polyangic : in Schizaeaceae and Azolla it is 
monangic, as in most Phanerogams. In the latter polysorous character 
occurs abnormally in Hesperis and normally in Cupressus , where outer 
integument bears on its dorsal surface several inner integuments con- 
taining nucelli. 
Lycopodiaceae . 
Isoetes : View of Celakovsk^ held that velum is equivalent to indusium 
of Ferns, and ligule to soriferous leaf-segment of latter ; hence sporan- 
gium along with these two organs = ovule with its two integuments. 
Lepidocarpon : * Integument ’ is probably equivalent to velum of Isoetes , 
but better developed, and thus to inner integument of ovule. Ligule is 
regarded as really situated outside the * integument’; the latter is merely 
a special modification of velum, which is here open at its distal end. 
