190 
ANNALS OP THE 
but the roots were found to be too small to be of much use. Since then, however, 
it has been improved by cultiviition ; the roots are figured as of the size and nearly 
the shape of an undersized early horn carrot. It is likely, therefore, to form a sub 
stantial addition to our culinary crops. 
It has been stated in the Gardeners' Chronicle that the Royal Horticultural So-' 
ciety bought up for their members all the good seed that was procurable, and this 
was to be distributed in small packets last month. It will, therefore, be satisfactory 
to the members of the Botanical Society of Canada to learn that our Society had 
previously secured a supply of seeds, which will be distributed to members in good 
time for sowing. 
ON THE DEVELOPMENT OF BOTRYDIUM GRANULATUM. 
Professor Lawson has given in the Edinburgh New Philosophical Journal for 
October, 1860, a lengthy description, with microscopical drawings, of a very inter- 
esting organism belonging to the group of Algae, which grows on the lake shore at 
Kingston. The following extract gives some of the general results arrived at in 
the paper, which enters fully into all the details of the plant's history. It is the 
Botrydium (Hydrogastrum) granulatura of modern botanists, and is believed to 
be identical with the " Bladder-headed Laver" found by Dillenius some hundred 
years ago, between ''Newington et Hackney, prope Londinum," as described by 
that author. 
The mature Botrydium consists of a transparent sac, branched in the lower 
part, filled with fluid, and containing in the upper part or head endochrome, in 
which are numerous spherules. This sac, which is very tougli and elastic, is dis- 
tended with the fluid contents, and consequently presents a turgid appearance. 
Thus, if pricked with a sharp point, the sac bursts, and the watery contents are 
squirted out with force, scattering the spherules. This may probably take place 
spontaneously. When exposed to drought, the sac collapses, and allows exit to the 
spores by its gradual dissolution. But one of the most curious tacts that I have to 
mention is one that probably explains the adaptation of the plant for its peculiar 
habitat. If a patch of Botnjdium in situ is covered with water for a few hours, and 
then examined, it will be found that the sacs have burst spontaneously and scatter- 
ed their contents, even althouuh they did not appear to be quite mature This re- 
sult seems to depend upon a process of endosmosis. Moisture is absorbed through 
the whole surface of the plant, and to such an e.xtent as to burst the already turgid 
sac, and thus the spherules are set free, and floated away from the parent, to form 
new colonies. While the collapsing of the plant by drought, and its gradual disso- 
lution on the subsequent application of moisture, is one means of permitting the 
freedom and development of the spherules, the inundation of the plant's habitat by 
