FORMATION OF SEBBS. 
T{ 
As specimens of the herbaceous roots are too large, and that Various speci- 
it would hardly be possible to give them within the prescribed 
limits for prints in this Journal, I shall present a drawing of 1 
a wood vessel fig. I, and an alburnum vessel with F, a closed 
one fig. 2, instead, to show how the flowers and seeds pass up 
the herbaceous plants from the root. So very quick is the 
passage of the buds up the wood cylinder, formed for the pur- 
pose, that if it is cut horizontally, arid left for an hour or two, 
the flowers will peep up above the wood vessels, and form a 
kind of nosegay or flower pot. It has always a spiral twisted 
up in the interior of the vessel apparently to keep it open, and 
prevent its pressing on the flowers within. As to the roots of 
herbaceous plants, it is impossible not to be struck with the 
astonishing difference between them and that part in trees, &c. 
The beautiful mechanism of the former is so admirable , that 
the mind finds it difficult, at first, to understand and discrimi- 
nate the particular parts, and it is only by comparing them with 
other sorts of roots, that 1 learned, at last, to comprehend the 
whole arrangement. The root is evidently the laboratory of The root the 
, , . , . . , laboratory of 
these plants, in which every different ingredient is composed herbaceous 
and concocted 3 and instead of the sameness and simple reguia- plants. 
rity of the root of trees, shrubs, &c. flowers, seeds, and spiral 
wire appear all in their allotted places $ and though annuals 
and herbaceous plants differ, yet it is too little to make it 
worthy discrimination, in so slight a sketch as this 3 nor does 
the bulb vary enough to particularize it, except to mention, 
that unlike the annuals, &c. the flowers mount in one or two 
cylinders only, instead of a circular row of wood vessels. T 
hJve described the formation of the plants that rise eath 3 and 
shall finish my letter by adding a few miscellaneous facts that 
increase the clearness of the general picture. 
I have also another discovery to make, which overcomes the Vacancies in- 
many difficulties which have appeared, such not only to other Vessels? SaP ' 
Phytologists, but myself also : I have said that when in trees, 
& c. the sap is cleared from the seeds in the alburnum vessels, it 
becomes a jelly, and then wood by the insertion of the different 
vessels, elongated from the neighbouring wood which also 
introduces the spiral wire, in every direction, to form the sap 
vacancies. Dr. Smith observes, in his excellent treatise on 
botany, that if wood is taken to pieces thread from thread, no 
sap 
