500 
POPULAR SCIENCE REVIEW. 
are developed the seeds, — sporangia : the deep colour of the mass 
is owing to the brownish yellow of these seeds. The other set 
of white veins appear to be formed of the unproductive sterile 
filaments, originating like the former primitive partitions ; but 
these veins or filaments being filled with air, present a dull 
white appearance when thin slices are examined by transmitted 
light. 
In these plants, therefore, we have a double system of veins 
or laminated filaments ; one set arising from the cortical 
tissue absorbing the surrounding moisture' and serving to 
transmit this to the cells in w T hich the spores are formed, being 
therefore the organs of nutrition ; the others white and opaque, 
terminating externally also, but conveying air to all parts of 
the body, and bringing the whole into contact with the spori- 
genous cells. 
The spores are developed freely in the vesicular cells des- 
tined to produce them. They are hmited in number in each 
vesicle ; less than two is never seen in one vesicle ; the hexa- 
gonal basket-work arrangement of each seed appears to close 
with a lid, and ten or twelve short spines project out from every 
point. 
Beneath the external dark-coloured reticulated membrane 
is a second integument, smooth and transparent, easily sepa- 
rated by maceration, although it resists the action of chemical 
agents, and is not coloured by iodine. The simple cavity of 
the internal spore is filled with minute granular particles and 
oleaginous globules, suspended in a fluid probably albuminous, 
as well as the various chemical salts found by Biegel. 
To proceed further with our microscopical investigation of 
the truffle will give no further insight into its minute structure, 
but it may be of interest to note a somewhat remarkable appear- 
ance during my examinations. Having cut the thinnest pos- 
sible sections with a cataract-knife, moistened them with a 
single drop of distilled water, and subjected them to pressure 
under a Powelhs compressorium, I watched with interest a 
series of currents round the circumference of the sections two- 
fold in direction. I, as usual, attributed these to the capillary 
action exerted between the plates of glass. Putting them aside 
for an hour and again examining them, this time using a higher 
power and eye-piece, I noticed an intense action was still going 
on all round the edge of the glass cover, exactly resembling the 
ciliary action round the mantle of the oyster ; at certain points 
losing the character of currents and presenting the appearance 
of myriads of atoms moving rapidly about, as in the phenome- 
non of “ swarming” amongst the Desmids. 
The sections were at the end of another hour removed from 
the compressorium, and kept moist by adding a drop of dilute 
