166 BOTANICAL GAZETTE. [July, 
found 95 per cent. bad. This accords nearly with my own deter- 
mination. We have, therefore, good physiological as well as 
morphological evidence that this Nuphar is in these localities a 
hybrid between N. advena and N. Kalmianum. 
But how is it with the same plant in Lake Champlain? It 
still remains associated with the other two species, but in some 
spots it has wandered to the distance of a mile or more from the 
others. At Ferrisbergh it is even more abundant than the pa- 
rental forms. It also bears an abundance of well developed fruit. 
I collected dozens, and could have collected scores of full, ripe 
berries. The grains of pollen in the freshly opened flowers were 
seattered freely over the stigmas, and proved, when examined 
microscopically, as sound as those of either N. advena or N. Kal- 
mian 
um. 
I am therefore led to believe that in this locality, on Lake 
Champlain at least, the hybrid has been developed into a good spe- 
cies, perfectly capable of propagating itself by seed; while in 
other places it still remains a hybrid and infertile. It seems to 
me that we have the transition complete, first the association of 
two species, next a mule progeny, and finally a new and _ perfect 
species. 
I have accordingly ventured to regard it as an undescribed 
species, and to call it N. rubrodiscum from its bright red stig- 
matic disk. 
To account for the blending of the two parental species in 80 
many instances, we are to remember the unusual facility of inter- 
course between them, which is possibly aided by some special 
innate tendency to assimilate. The flowers of both are very con- 
spicuous on the surface of the water, for one thing, and when in 
fresh blossom the corolla is frequently full of small winged in- 
sects. I scarcely opened a flower but I found a host of these 
visitors either upon the stamens or the nectaries. I also noticed 
a variety of aquatic insects which seemed to make their home 
n the leaves and stalks, and to dispute possession of the 
flowers with their winged rivals. Now here we have a means of 
spreading the pollen from one flower to another, which is n° 
doubt very effective. The plants also flower all summer long, 
beginning in May and continuing till September. Besides this 
they grow generally in quiet water and sheltered nooks where 
they are protected from disturbing winds and waves. We should 
therefore expect just such results as we have if there were any 
hybridizing tendency at all in the species. 
I have been led on by interest in these three related forms to 
look up the other North American species of Nuphar, and the 
following is offered as a revision of the genus: 
