248 PROCEEDINGS : BOSTON SOCIETY NATURAL HISTORY. 
pistillate colonies they are often very scarce. In the other three 
species staminate plants are either quite unknown or else exceed¬ 
ingly rare. A. neodioica , which is abundant in New England, is 
known with us only as a pistillate plant. Further south, however, in 
Pennsylvania and Virginia, the staminate plants, according to Pro¬ 
fessor Greene, are frequent. Among thousands of specimens of 
A. canadensis , which have been examined from all over northern 
New England, only two stations of staminate plants have been 
detected; and in the case of the very characteristic A. parlinii , 
though many acute observers have watched in New England, only 
pistillate plants have thus far been found. Further south and west, 
however, staminate specimens of the two varieties have been col¬ 
lected. In these cases of A. neodioica , A. parlinii , if not likewise 
A. canadensis , though staminate plants may yet be detected, it must 
be apparent that they are very unusual. In the cases w T here staminate 
plants are known, it is noteworthy that the pollen is apparently very 
early discharged, at least the staminate inflorescence very quickly 
shrivels, though it remains entirely recognizable for a long time 
thereafter. In New England, then, so far as the evidence yet 
shows, of the six species only three have staminate plants in any 
abundance, though a fourth is known rarely to produce them. 
The question must arise, how are these plants perpetuated, and do 
they all produce seed ? From a superficial examination the akenes 
of all the species seem plump and as full of vitality as those of most 
Compositae. I am not aware, though, that any one has made tests 
of-their fertility. Professor Greene asserts that the seeds of these 
plants are good, 1 though I cannot state to what extent he has 
experimented with them; and from this decision he draws the 
inference that we may here have a case of parthenogenesis. 
Another possibility has presented itself, that the ovaries of these 
plants may be fertilized by pollen from what seem superficially to 
be quite different species. In southern New England, where the 
staminate plants of A. plantaginea are not rare, this might not be 
absolutely impossible ; but in the Franconia region, where one of 
the keenest of our New England observers, Mr. Edwin Faxon, has 
found no trace of that species, and got staminate plants of only 
A. neglecta , — shrivelled long before the other species begin to 
bloom, — such an explanation seems very unsatisfactory. In north¬ 
ern Maine, too, where no A. plantaginea w r as found, I examined 
1 Plant world, vol 1, p. 102. 
