TRANSACTIONS OF THE SECTIONS. 103 



have supposed. To determine the manner of germination, some seeds 

 were placed in water in watch glasses, seeds alone, and seeds with 

 granules, in separate glasses, and in a few days the seeds appeared 

 swollen about the apex, which became of a blackish brown colour, and 

 in a few days more a green point presented itself in a direction vertical 

 to the axis of the seed and became a leaf. The leaf having attained 

 about half an inch in length a white radicle appeared in the opposite 

 direction. When the root had grown about half an inch the young 

 plants all died, probably from exposure to too much light, and from being 

 deprived of other advantages which soil might afford. Suspecting this 

 might be the cause, a glass vessel was nearly filled with mud and water, 

 which was covered by a bell glass, and a number of seeds placed on the 

 surface of the mud and others buried a little below : germination soon 

 commenced, but in this experiment the first leaf proceeded at right an- 

 gles to the axis of the seed. Tlie leaf invariably appeared before the 

 radicle. In about a week a second leaf and radicle, and again a third 

 appeared, with a rudiment of an horizontal stem, proceeding from the 

 point of union between the first leaf and root. The seed or rather the 

 external covering . remained attached to the plants for many weeks. 

 The number of leaves and roots previous to the appearance of the stem 

 is uncertain in different plants, llie first leaf is perfectly straight from 

 its first commencement, but all succeeding leaves are coiled after the 

 manner of the fronds of ferns. 



The plants obtained from the latter experiment are still growing, 

 though indicating no signs of fructification at present. 



The embryo in all cases proceeds from one determinate point at the 

 apex of the seed, which is plainly discernible in the seed in all its 

 stages of development, at first in the shape of a minute conical point, 

 gradually contracting and flattening ; and when the seed is matured it 

 appears, like a circular opening closed by minute converging teeth, 

 through which the seminal leaf protrudes. The circulation of the sap 

 seems to be carried on chiefly by endosmose and exosmose, as the sub- 

 stance of the stems and leaves consists for the most part of oblong cells 

 of various sizes, their extremities being closed ; but in the centre of 

 both stem and leaf may be observed a bundle of vessels of minute 

 dimensions which appear to be ducts. No spiral vessels could be 

 detected. Professor Lindley has noticed ducts in Marsilia. The de- 

 velopment of the seminal leaf in Pilularia before the radicle is analogous 

 to the germination of some of the Cyperacese, as, according to Mirbel, 

 in Scirpus sylvaticus, &c. The habit of this plant also resembles some 

 of the species of that order. When it is considered that so many of the 

 essential characters of the cellulares do not apply to the Marsiliacese, as 

 in the plant in question, the embryo proceeding uniformly from a deter- 

 minate point of the seed, the stems and leaves being vascular, and no 

 other order of the cellulares having a true stem or so perfect an or- 

 ganization, it leads to the conclusion that this order is intermediate be- 

 tween the monocotelydons and the cellulares, or at least first among 

 the latter, as Mirbel and some other continental botanists have placed it. 



