NIADACEZ. 179 
passages opaque. These two form the firm part. 
. Then continuously radiating lax spongy tissue, cells and 
passages opaque by air, particularly the latter, so lax 
thata thin section is difficult. 
. Then a small ring of white cellular tissue. 
. And then the cutis or cuticular tissue which is thickish 
and opaque. 
e 
S us 
NIADACELE. 
General Remarks. 
The Indian species of Naias, are neither Caulinez or Naia- 
des of Endlicher, having the anthers of the former according 
to his definition, with the naked females of the latter. 
There are certain appearances connected with the Pistillum 
that leads me to suspect that Caulineæ have not been exactly 
described : for there is an appearance of a tunic gradually los- 
ing itself up the style, but which certainly does not depend 
upon any great peculiarity of structure, I shall not be at all 
surprised if Endlicher's descriptions of the females of both 
аге faulty, he says that the epicarpium of Naias is mem- 
branous and becomes detached ! 
The structure or development is remarkable, and that parti- 
cular line of gradation which enables us to identify dissimilar 
structures at different periods of development, is so obscur- 
ed, that Iam unwilling to speak confidently of the male 
and female organs at a very early period. 
The earliest? identical character of the female, is to be 
found in the oblong shape of the pistillum, which will be found 
broadly open at the apex, the orifice being somewhat bi-lobed, 
the nucleus reaches to the fundus of the orifice, but is not ex- 
serted, 
I have seen no gradation of development of the outer tunic 
of the male: the transition from a rudimentary i naked 
stamen, to a full formed one, appearing to be remarkably sud- 
