272 
The very puzzling specimens from Wenham Pond, Mass., 
would, I think, be placed to P. undulatus, Wolfgang (P. perfoliatus 
X crispus, according to Mr. Fryer); but here comes in a very im- 
portant question: supposing this to be an admitted fact, and also 
admitting that P. crispus, L., is an introduced plant to U.S. A., 
then the Wenham plant must be a very recent production of hy- 
bridity ; the plant will well bear careful study. 
It would be a matter of some interest to trace back to the 
earliest date possible the specimens of P. crispus gathered in North 
America; my friend, N. C. Melvill, has a specimen from “ Phila- 
delphia, 1841-2,” gathered by “ Gavin, Wakon and Kilvington.” 
In marking a map of the world (on Mercator’s projection) with 
the localities of P. crvispus, it will at once be seen that, leaving the 
United States localities out, all fall within the right hand side of 
the 10° of west longitude. On the one hand, the British Isles 
seem the nearest to North America; on the other, Queensland in 
Australia. I have not seen it from New Zealand. It is certainly 
the most likely species to become transported to other lands, by 
its hardened winter-buds, which will equally bear exposure on dry 
mud or being frozen in ice. My friend, Mr. Straher, informs me 
that he finds that wherever horses have access to ponds there P. 
crispus is found, but where they are fenced round and not acces- 
sible to them, he has never found it; this is the result of the ex- 
amination of a large number of ponds in Surrey. I cannot 
myself say I have ever noticed this, and it should be verified over 
a larger extent of country. 
Dr. Morong makes the P. pusillus, var. major, Fries, into a spe- 
cies, under the name of P. major (Fries) Morong. To this I 
cannot assent, as there is already an undoubted specific name ine 
P. Friesti, Ruprecht, of which I have seen numerous specimens 
from Ruprecht’s own hand. I cannot say that I see the need of 
dropping P. hybridus, Michx., because Pentagna (not Thuillier), in 
Inst. Bot. 2, p. 289, 1787,so named a plant which is not Michaux’s. 3 
P. pectinatus, L., and its allied species, or what we choose to 
call them, will give plenty of work to botanists for some time. 
Applying Dr. Morong’s own test, his name P. /atifolius is not 
admissible, as Robbins overlooked that there was already a P. pec 
tinatus, var. latifolius, Meyer, Ch. Hann (1836), therefore his name 
