Heir-apparent of Ava. 27^ 
omitted, although several of them pass through the country 
here delineated. - 
A torrent called Paenwa, not connected with these branches 
of the Paunlaun, and omitted by the native of Taunu, has been 
laid down in this map. It rises near a town called Paen, and, 
on the 6th of November, when I was at its mouth, I found it 
nearly dry. The people on the spot called it Paenghiaun, or the 
Paen Torrent, and gave the name Paenwa to a small town at its 
mouth, which serves as a port for the trade of Preen Mro, the 
city at its source. 
Art. XI. — New Inquiries into the Laws which are observed in 
the Distribution, of Vegetable Forms. By Baron Alexan^ 
DEii Humboldt , 
T? HE numerical proportions of vegetable forms may be view- 
ed in two perfectly distinct lights. If we consider plants, group- 
ed together in natural families, without having regard to their 
geographical distribution, we enquire what are the types of or- 
ganization, according to which the greatest number of species 
are formed. Are there more Glumaceae than Composite on the 
globe ? Do these two tribes of vegetables constitute together 
the fourth part of Phaenogamous plants ? What is the pro- 
portion of Monocotyledones to the Dicotyledones ? These are 
questions of general Phytology-— of the sciences which examine 
the organization and mutual connection of vegetables. If we 
view the species which we associate according to the analogy of 
their form, not in an abstract manner, but with regard to their 
climacteric relations, or their distribution over the surface of 
the globe, the questions which arise afford an interest highly 
varied. What are the families of plants which predominate 
over the other phsenogamous vegetables more within the tor- 
rid zone than under the polar circle ? Are the Composite more 
numerous, either in the same geographical latitude, or on the 
same isothermal band, in the new Continent than in the old ? 
Do the types which predominate less in advancing from the 
* A separate copy of this memoir was sent to us by the author for insertion in 
fiur Journal, through Dr Marcet. 
