952 
detailed résumé of the results, are given. Of 
particular interest in the contents of thejpam- 
phlet is the account of the magnificent building 
which is now nearing completion on the rock 
of Monaco, andintended to contain the great 
zoological and other collections of the Prince. 
The foundation stone was laid on April 25, 
1899, by the Emperor of Germany. An idea of 
the size of the structure may be had from the 
fact that the facade will have the length of one 
hundred meters. While the greater part of the 
exhibits will relate to the biological sciences, 
there will be considerable space given to the 
illustration of apparatus, of the physical condi- 
tions of lifein the sea, and of the areal and, 
bathymetric distribution of organisms, by means 
of charts, diagrams, photographs, water-color 
sketches, ete. Appended to Richard’s work is 
a valuable bibliography of the publications of 
the Prince and of his collaborators on the col- 
lections of the ‘ Hirondelle’ and the ‘ Princesse 
Alice.’ 
MARINE CURRENTS AND RIVER -DEFLECTION. 
THE cause of the strong left-hand deflection 
of the Mississippi River below Baton Rouge has 
long been a matter of discussion (Fig. 1). The 
decided asymmetry of the delta both above and 
below sea level is an associated problem. Wind 
Fic. 1. The delta of the Mississippi. 
indicates older land. The arrow shows the general 
direction of the marine current prevailing at the river 
mouths. 
Cross-lining 
direction, the influence of the Red River and 
crustal warping have been in turn appealed toin 
explanation of the facts. The formerly credited 
clockwise movement of the Gulf Stream in the 
Gulf of Mexico has likewise been held respon- 
sible. It is now generally agreed, however, 
SCIENCE. 
[N.S. Vou. XIII. No. 337. 
that the prevailing direction of current move- 
ment is really westward past the mouths of the 
river. Haskell proved this by the use of the 
current meter on board the Blake. Lindenkohl’s 
chart of densities plainly shows a transference 
of Mississippi water toward the west as it 
spreads out over the Gulf. The cause of the 
current is indicated in the prevailing easterly 
winds, as charted, for example, in the new 
Meteorological Atlas of Bartholomew. Corthell 
has noted a maximum speed of three knots for 
the west-flowing current. 
In view of such strong and accumulating 
evidence for the current, it becomes of interest 
to inquire as to its influence on the form of the 
delta. The presentation of the case may suf- 
fice to call attention to a possible kind of inter- 
action between river current and ocean current 
in the development of a very definite type of 
form. 
Outside the river-bars, aggradation of the sea 
floor is progressing more rapidly on the west 
than on the east of the delta. The striking 
asymmetry of the delta is thus in part explained. 
The deeper water on the east will particularly 
facilitate the yearly advance of the bars on that 
side. Butthe direction of advance will be affect- 
ed by a more positive cause. It is well known 
that the bar at each passis breached during the — 
flood season, and beyond the lower end of the 
new channel the delta is pushed forward for the 
remainder of the season. While the bar thus 
built in a new position is left essentially undis- 
turbed by the river itself during the following 
half-year of low water, the transverse Gulf 
current (which is aided in the work by 
westward drift in the Tine of breakers on the 
bar) may be conceived as modifying the form 
of the bar during same period. The bar will 
be weakened on the left-hand extremity where 
the impact of the current is first felt, and 
strengthened on the right by the accretion of the 
silt traveling under the impulse of the cur- 
rent thus along the axis of the bar. The 
right-hand extremity of the bar will also tend 
to grow the faster in height and breadth, be- 
cause of the sedimentation occurring in the low 
water season, since the river water over the 
bar is then borne upon the back of a west-flow- 
ing salt water wedge. The left-hand extrem- 
