880 NOTES ON PONDWEEDS. 
is a species? a question not lightly to be answered, nor ; 
settled. Space would be uselessly filled b any recapitulation 
of definitions now known to every student. But one thing may 
weeds of a single country, but arguing from what we see at home, 
it seems very improbable that even the most sharply defined forms 
te 
era. 
1s note is already too long, so the description of P. lucens 
: xt. Space is only left to say, once 
again, that abnormal variations soon resume their normal appear- 
i h 
vations made in the field, alike tend to suggest the expediency of 
U 8s : d 
dealing our multiform Pondweeds as specifically ‘fixe 
quantities.” * 
‘i aaa cre ssp escapes een ee NTE Se m 
- ‘ By us, as least as workers, species must be dealt with as fixed quan- 
‘fities.”—Mr. Carruthers, Journ. Bot. 1886. 
