378 Mr. Hodd's Observations on the Spongilla fluviatilis, 
Professor Don, by whose kind assistance I was enabled to see these bodies 
magnified 400 times: even at such a high power we both were unable to 
discern the presence of any cilia, but most distinctly observed the entire 
covering or membrane of the sporules to be ‘studded al! over with short pa- 
pilla. Now it is very probable that the currents in the water, which I sup- 
posed to have been caused by the rapid vibrations of tufts of cilia, were cur- 
rents produced by a reciprocal action, or, to use the terms of M. Dutrochet, 
by an endosmosis and exosmosis, i.e. by an inward and an outward impul- 
sion of fluids, not only through the membranes of these sporules, but also 
through these membranaceous papillæ, in accordance with the discoveries of 
that distinguished physiologist. Wherefore, the currents so produced would 
I conceive be a satisfactory mode of accounting for the singular and beautiful 
phenomenon of locomotion as exhibited in these sporules; and it is in pur- 
suance of the philosophical views of Mr. Berkeley, F.L.S., as briefly mentioned 
by him in a paper * On the supposed Animal Nature of the Seeds of certain 
Alge, published at p. 233 of Hookers Journal of Botany, part 3, for July 
1834* ; although, if this hypothesis should ultimately not prove the correct one, 
we must endeavour at another opportunity to investigate the causes of that 
interesting phenomenon by a more minute and complete examination of the pa- 
pille with which those sporules are so abundantly furnished, and whilst they 
are in a fresh state; for indeed I cannot but imagine that the function of loco- 
motion must be in part carried on by means of the currents which I noticed in the 
water, proceeding from the sporules, and very possibly effected in some degree 
by a peculiar, but as yet unknown, faculty of the papillz themselves. 
Hence, from what has been said, it will be evident that locomotion being 
common both to some bodies pertaining to plants, and also to animals, the 
i; * I think it better to insert here from that work Mr. Berkeley's own explanation of what he thinks 
the = "e to be: “ When the seed separates from the matrix, it passes into the water in which the 
plant is immersed. Now if the contents of the seed, which are semifluid, are of a different specific 
gravity from that of water, a mutual action of exosmose and endosmose will immediately take place 
through the epidermis of the seed: the water will pass into the seed, and part of the fluid matter of 
the seed will pass out into the water; and in consequence of this action, the current produced will 
cause the seed to move about, until an equilibrium take place, when the seeds will settle at the bottom 
and begin to vegetate." See, for additional remarks on the same subject, p. 28 of Berkeley's “ Glean- 
ings of British Alge, Lond. 1833, where in plate x. the Ectosperma clavata is well represented. 
