Botany and Zoology. 437 
British gatherings. Yet all these forms were supposed, not long since, 
to be exclusively fossil. We cannot say that there are no species ex- 
clusively fossil, but so many that have been thought so are daily found 
living, that it is probable the rest may be so found too, and at all events, 
a very large proportion of the forms in the oldest fossil deposits are 
absolutely identical with the forms of the present day. 
Ihave only further to mention, that although so many species are 
universal in their habitat, some appear to be local. ‘Thus, Terpsinoé 
musica does not occur in Europe, nor has it yet been found except in 
America, and, I think, in Australia. 
Some species are decidedly Alpine ; for example, Orthosira spinosa, 
which Professor Smith found on the Mont d’Or in Auvergne, and Pro- 
fessor Balfour on the Grampians. It occurs also in nearly every soil 
from the Andes. 
5. On the Injurious Effects of an excess or want of Heat and Light 
on the Aquarium; by Roperr Warineton, Esq., (Ann. Mag. Nat. 
Hist., vol. xvi p. 313.) —Temperature is a point requiring great atten- 
tion in carrying out successfully the principles of a permanent aquarium. 
The mean temperature of the ocean is estimated to be about 56° Fahr. 
and this, under ordinary circumstances, does not vary more than about 
12° throughout the different seasons of the year. The causes of this 
equilibrium will be readily understood when we take into consideration 
the effects that must be produced by the continued flux and reflux o 
the tides, and by the enormous streams of water which must be flowing 
from the Arctic regions from year’s end to year’s end in one constant 
current, and which, by their movement, must necessarily cause other 
currents to flow in and take their place, thus forcing, as it were, the 
heated surface-water of the tropical seas towards the colder regions of 
the globe. Again, the whole surface of the earth, submersed below 
them rapidly to move their position and seek some cooler or warmer 
Spot as the case may be. In the ocean it will be evident that the crea- 
from the heat of the sun’s rays on the ot : 
From my own experience I find that the range of temperature should 
to progress healthily, but beyond these points many of the creatures 
are rapidly affected. During the last long-continued and severe winter, 
