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 Cyperacea, 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 Marsiliaceas, 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 and 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 Anglica. 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. 



Ornithopus perpusillus. Sandy fields, frequent, as at Prestwich. 



Lythrum salicaria. Carrick-hill, &c — wet places, very frequent. 



Sedum telephlum. Rocks near Dunure, and elsewhere on the shore — fre- 

 quent. 



Sedum anglicum. 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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