296 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
for finally settling the vertical distribution of pelagic life than off 
Savanna, which is in deep water, close to the track of the Gulf Stream, 
which is remarkable for the mass of pelagic life which it carries along its 
course ; he towed in 100, 150, 250, and 300 fathoms, and for an equal time 
on the surface, at or near the same locality. At no depth did he obtain 
with the Tanner net any species which were not also at some time found 
at the surface. Even at 100 fathoms the amount of animal life was 
much less than in the belt from the surface to that depth. At 150 
fathoms there was still less, and at 250 and 300 fathoms the closed 
part of the Tanner net contained nothing. This, Prof. Agassiz points 
out, is in accordance with the observations of the Plankton expedition 
so far as they have been published. He adds that many observations 
which formed the basis of statements proving the indefinite extension 
in depth of the pelagic fauna and flora, are of little value, owing to the 
imperfect working of the apparatus used. In a towing for 20 minutes, 
at a depth from 100 to 110 fathoms, only one Copepod was brought up 
from that depth, while in the open part of the net he obtained several 
specimens of Eucope , many pails of DipJiyes, numerous Copepods, 
Alciope, Schizopods, larvae of Brachyurans, Macrurans, Doliolum , Appen- 
dicularia , Gastropod larvae, and Collozoum. A second tow at 800 fathoms 
resulted in the closed part of the net containing nothing, and an 
examination of the contents of the open part of the net, which re- 
mained open from 300 fathoms to the surface, showed that it contained 
nothing that had not been obtained from the shallower depths between 
the surface and 100 fathoms. Other observations resulted in very 
similar kinds of collections. 
Theory of Descent and Heredity.* — Prof. C. Emery directs atten- 
tion to Fabre’s thesis that instincts do not vary as such (though they 
may be modified by intelligence), that they are distinct and fixed for each 
species, and that they show evidence of gradual evolution from simpler 
instincts. It may be noticed that this is just what used to be said of 
structural characters, and is mainly an argumentum ad ignorantiam. 
But Emery’s solution is that the instincts, to whose evolution we have 
no clue, are cases of “ saltatory evolution ” — abrupt variations. 
The author then discusses budding. In sessile organisms, such as 
Hydroids, liable to have parts bitten off, it was probably at first a pro- 
cess of regeneration, adaptive in origin. He dissents from Weismann’s 
view, that budding is traceable to a sort of parthenogenesis or sporulation 
of special cells, one for each bud. Such a case as Ccenurus he regards 
as due to the hereditary fixing of a teratological multiplicity, comparable 
to poly-embryony, and finds in it another instance of saltatory evolution. 
Emery does not seem to attach any primary importance to the conspicu- 
ously vegetative condition of most animals which bud. 
Darwinism and Experiment.! — Herr G. Wolff has some criticisms 
on the theory of natural selection. He believes Darwinism is breaking 
up : “ Es mehren sich die Anzeichen, dass die Episode des Darwinismus 
iiberwunden werden wird.” Episode, forsooth ! The theory does not ex- 
plain origins , the chances of a fit variation arising are small except in the 
case of gradual progressive change, and so on, as has been said before. 
* Biol. Centralbl., xiv. (1894) pp. 721-7. 
f Tom. cit., pp. 609-20. 
