170 : 
ra 
the market. The price is remarkably low.—9. Zhe Chautauqua 
Flora, by Edward S. Burgess, Clinton, N. Y: This includes the 
cryptogams to the end of Hepatice. There are 37 lithographed 
pages, 880 species. Mr. Burgess deserves credit for his enterprise. 
We notice that he gives no Cistacee. We wish much that those 
who have knowledge of this order would help us in fixing the limits 
of the species on this side of the Rocky Mountains. Mr. Burgess 
reports a pink-white variety of Pontederia, found by Mr. Geo. Miner. 
There seem to be no Cassias in Chautauqua, 49 Carices, and 30 
Ferns.—10. Hay Fever or Pollen Poisoning: In this essay, reprinted 
from the Transactions of the Medical Society of New Jersey, 
Newark, 1877, Dr. Elias J. Marsh, of Paterson, seeks to maintain, as 
others have done before, that the rose and hay fever, the former in 
early, the latter in late summer, are caused by pollen floating in the 
air; in particular the hay fever by the pollen of Ambrosia. It would 
seem likely enough that susceptible constitutions may be irritated 
by such agencies, especially as certain regions, sharply marked, are 
found to be free from the exciting cause, but more accurate obser- 
vations are needed. We notice one or two botanical misprints. 
Ambrosia trifolia should be A. trifida. How did the Dr. recognize 
the pollen of Ambrosia in the air? It is apparently an anemophilous 
plant, and very probably the pollen is peculiar, and, if certainly identi- 
fied, the observations would be interesting on that account.—r1. 
Science Observer, No. 2, Boston, Mass., Boston Amateur Scientific 
Society, 4 pages monthly, 25 cents per annum. Solicits exchanges. 
The present No. is chiefly Astronomical and Mineralogical. 
§ 177. Pontederia cordata, L.—On page 62 of this volume of 
the BULLETIN, I gave some observations on this plant, but working 
with dried specimens, I did not make out its character truly and 
supposed the lengthening of the style in the coiled up flowers to be 
a result of growth or tension. ‘There is | believe such an extension, 
but not to the degree supposed. 
This summer, I had the opportunity of seeing some growing 
plants, and find that Pontederia is as truly trimorphic as Lythrum 
Salicaria, or even more so. There are three kinds of flowers, not on 
the same but on different plants. Of these, one has the stigma raised 
on the style to the top of the flower, a second only to the middle of 
the flower or top of the tube, and the third with a very short style ‘at 
the bottom of the tube. There are thus three positions for the 
stigma. Whenever the stigma is in one of these positions, the two 
other are occupied respectively by one of the two sets of anthers, 
three ina set. When the anthers occupy the highest position their 
pollen is, I judge about 1% thousandths of an inch in diameter. 
Anthers occupying the middle position have pollen rather smaller, 
say 14 thousandths of an inch in diameter. When at the bottom ot 
the tube, the anthers have still smaller pollen, say 1 thousandth of 
an inch or less. The pollen in all positions seems to be perfect. It 
remains to be seen whether all forms ripen seed equally. The 
stigma of the tallest style is plainly cut into six linear segments. If 
there is any division of the other stigmas, it is not very manifest. 
The stamens of each set are not quite uniform in length, and in 
