498 Botany. 
axis of the seed. The leaf in this experiment also preceded the radicle. In a week 
or more, a second leaf appeared, and in about the same length of time a third with 
a rudiment of a horizontal stem proceeding from the point of union between the 
radicle and first leaf. The seed or rather the external coriaceous covering adhered 
for many weeks. The number of leaves and roots previous to the developement 
of the stem, is various, in different individuals. The first leaf is straight from its 
earliest appearance, but all the future leaves are slightly coiled, as in the young 
fronds of ferns. It is observed that in all cases the embryo proceeds from the 
same determinate point of the seed. The circulation of the sap seems to be 
carried on by Exosmose and Endosmose, as the substance of the leaves and stem 
consists chiefly of elongated cells of various dimensions, their extremities being 
closed by partitions ; but in the centre of the leaf there is a branch of vessels 
which appear to be ducts of very minute size. No spiral vessels could be de- 
tected. Professor Lindley has observed ducts in Marsilea. The developement 
of the seminal or first leaf before the radicle is analogous to the germination of 
some of the Cyperaceae, as according to Mirbel in Scirpus Romanus, sylva- 
ticus, 8f c. 
The habit of Pilularia also resembles that of some of the same order. When 
it is considered that so many of the essential characters of the Cellulares do not 
apply to the Marsiliaceae, as in the subject of the above observations, the embryo 
proceeding from a determinate point of the seed, the vascularity of the stems 
and leaves, there being no other order of the Cellulares having true stems, and 
the approximation to a sexual apparatus, it seems to point to the conclusion that 
this order is intermediate between the Monocoteledones arid the Cellulares, or 
at least should stand first among the latter as Mirbel and some other Continen- 
tal botanists have placed it. Lloyd. 
Contributions to the Flora of Ayrshire. 
Teesdalia nudicaulis. Sandy fields, near Prestwich. 
Lepidium campestre. Near Dunure Castle. 
" Raphanus maritimus. Ailsa Craig Mr Jas. Smith." 
Silene Ariglica. Sandy fields, near Prestwich rare. 
Spergula saginoides et subulata, Carrick-hill very rare. 
Radiola melligrana. Prestwich Moor, in many places. 
" Lavatera arborea. Ailsa Craig Mr J. Smith." 
" Hypericum montanum. Banks of the Doon, near Cassilis Mr Jas. Smith." 
Hypericum elodes. Lochfergus Irvine not uncommon. 
" Geranium columbinum. Near Maybole Mr J. Smith." 
Trifolium ornithopodioides. Shore near the mouth of the Doon, where sea- 
weed has been Dr G. M'Nab. 
Omithopus perpusillus. Sandy fields, frequent, as at Prestwich. 
Lythrum salicaria. Carrick-hill, &c. wet places, very frequent. 
Sedum telephium. Rocks near Dunure, and elsewhere on the shore fre- 
quent. 
Sedum anglicurn. Rocks, especially on the shore common. 
Rhodiola rosea. Rocks on the shore, south of the Heads of Ayr. 
Saxifraga aizoides. Rarely with the preceding. 
" Saxifraga hypnoides. In a glen, near Dalmellington Dr G. M'Nab." 
" Carum verticillatum. Near Dalrymple, and elsewhere' Mr J. Smith." 
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