6 
the leaf inwards and fuse them together so 
that the grorving points were turned inwards 
towards the central part or axis of the ovary 
you would have a typical example of that 
organ. But this is not a lecture on Botany, 
so I have to leave this subject with the re¬ 
mark that the flower of this Bryophyllum is 
of itself very remarkable having four (some¬ 
times only three) separate carpels each with 
a very long style and eight (or often seven) 
stamens, the whole inclosed in a tubulai 
corolla which is again inclosed in a kind of 
campanulate calyx. These floral envelopes 
are quadriparite. The rule of five prevails 
generally among exogens, bub there are 
many departures from and exceptions to this 
rule 'and this is one of them. We must 
leave the station yard or we might find 
matter to keep us there all day even if we con¬ 
fined ourselves to the botanical department 
alone. Most of the ground is covered with 
ordinary weeds, but an array of cultivated 
shrubs and flowering plants brightens up the 
space adjoining the platform which we now 
leave and pass on to the main road which 
we have to cross in order to pursue our 
excursion. In doing this we observe heaps 
of road material piled by the side of the 
road in readiness for repairs. On examina¬ 
tion we find these to consist chiefly of the 
dark-coloured compact limestone quarried in 
the neighbourhood of Port-of-Spain, some of 
which is veined with caleite, the latter being 
the port ion of the limestone dissolved out by 
water and deposited in veins and Assures of 
the rock. Nearby we And some fragments 
of a material closely resembling at a cur¬ 
sory glance this calcite . This on examination 
turns out to be milk white quartz. Here an 
elementary piece of mineralogical knowl¬ 
edge comes to our aid to enable us to 
distinguish the dilference and shows the 
value of even a smattering of such knowledge. 
Had we some dilute acid with us we might 
apply it as a test : for the limestone and 
its included calcite would effervesce freely 
with it. But we have no test at hand 
except our knives. These will do very 
well ; we scratch the limestone and 
the calcite with a penknife and the 
result is a streak of white powder, while 
the same operation performed on the quartz 
fails to scratch, but leaves a dark coloured 
streak of metal on the stone Of course, the 
cleavage andcrystallineforms are sufficient to 
the eye of a mineralogist without even the 
use of a simple test such as I have given to 
determine the difference between quartz and 
calcite. The piece of calcite I am now showing 
