30G 
THE GEOLOGIST. 
It may be inferred from this succinct analysis of the physical part of 
Dr. Lorenz's book, that it is, in itself, and independently of the organogra- 
phical division, a highly valuable contribution to our knowledge of archi- 
pelagic hydrograph5^ must wish, therefore, to see the author pur- 
suing the plan, traced out in his epistolary communications, for stating the 
essential, nvimerous, and practically interesting differences between the 
simple conditions of oceanic and the far more comphcated ones of archi- 
pelagic hydrography. The organographical division begins with intro- 
ductory remarks on the method of investigation and the way of discussing 
their results. It is proved to be m.ore adequate and conclusive not to 
begin with the statement of regional limits, but rather to state regional 
maxima, from which the organic types most evidently consociated within 
the maximal strata may be pursued in ascending and descending directions 
as far as to their extreme limits. Anim.al and vegetable forms must not 
be prom.iscuously used for regional elements, as it has been done by Oersted 
and partly also by E, Forbes, the plants following, in their distribution, 
quite different laws from animals, tlie maximum of their diversity of 
forms and their total disappearance taking place in depths entirely dif- 
ferent from those of animal organisms. The purpose of the method fol- 
lowed by the author in the description of each region is, to give a complete 
physiognomical and actiognomical idea of each of them as to their causes, so 
as to serve as points of comparison for future similar investigations, — a pur- 
pose not attainable from the majority of the hitherto published marine faunce 
and florse, these being generally mere enumerations of species. 
The detailed descriptions begin with the marine plants of the Quarnero. 
Every region is accompanied by special details in respect to its physical 
conditions, founded on careful local investigations. By this method, the 
simple mention of the depth in which any organic being is living is quite 
sufficient to give an exact notion of the whole of the external agents under 
which it exists, and which, more or less, are determinative of its habitat. 
Within every region of depth organic beings are consociated in dis- 
tinct groups, as far as the conditions, not essentially connected with depth 
and consequently diversel}^ distributed within one and the same stratum 
of depth, as the nature of the sea-bottom, currents, and, in higher strata, 
undulatory movements, affiuence of fresh water, etc., are more or less fa- 
vourable to their development. 
These groups distinguishable within each region are called "fades." 
The author enumerates forty-one of such facies within the six vegetable 
regions of the Quarnero, and names them according to the genus prevailing 
among them, Callithamnetum, Cystoseinetum, etc. 
A table of distribution enumerates the vegetable species in systematic 
order, each with the corresponding number of its region, and its horizontal 
range in other seas. A comparative synopsis of the vegetable regions of 
the Quarnero and of those of other seas, shows Oersted's book on the 
Oeresund to be still the only extant work on marine plants and their dis- 
tribution which may afford profitable comparative results. 
The seven regions and thirty-two facies of the Quarnerian animals are 
treated on the same plans as those for vegetables, both of them standing 
frequently in mutual dependence. 
The table of distribution of animals gives a comparative view of the 
depth at which the same species have been found in other seas by E. 
Eorbes, Oersted, and M'Andrew, and of their horizontal range, as far as 
yet ascertained. 
Also for the animals a comparative synopsis again proves the results 
obtained by E. Forbes and Oersted to be the only ones fit for profitable 
comparison. 
