and lastly the Glumaceous. How far these five groups are strengthened by 
variations in the conformation of seed, Iam as yet unable to say, not having | 
given that attention to the subject which it requires, but I apprehend when they 
also are closely examined, with special reference to this enquiry, that many points 
in confirmation of their stability will be found and, with their aid, a series of 
perfect circles be discovered presenting striking analogies with others referable 
to the exogenous circle. Until however this is effected Lindley’s very practical, 
I think also most natural distribution of these tribes, leaves little to be desired 
by the practical botanist. 
_ Onthe last great division of the vegetable kingdom the Acrogens or Cryp- 
togamic plants I have nothing to add to what I have already said. This group 
certainly forms the aberrant circle, and like the analogous circles in the animal 
kingdom is made up of three Balaller ones, each of which seems complete, though 
all require verification. 
For those wishing to acquire a deeper insight into the science of plants than 
these pages can possibly supply, I would particularly recommend the study of 
Dr. Lindley’s Elementary Botanical works which are by far the best in the 
English language. His recently published Vegetable Kingdom I have not yet 
seen, but it is very highly spoken of by two of my Correspondents who have. In 
its arrangement, I learn, he has considerably departed from both those referred 
to above, as given inhis Elements and Natural System, falling back in a great 
measure on the plan of Jussieu, but greatly improved. To those desirous of be- 
coming acquainted with the first principles, and many of the details of the cir- 
cular system of classification, Swainson’s volumes of Lardner’s Cyclopedia are 
the only easily procurable text books and are among the most interesting volumes 
I ever read on Natural History, 
