186 The American Naturalist. [February, 
ing the local mineralogists an opportunity to study and collect feldspar, 
' quartz and mica, with associated garnets and tourmalines and is a 
suggestion as well of the underlying reefs of archæan metamorphic 
masses upon which our own island is built, and our geological relation- 
ship with New York from whose ledges the rocks have been trans- 
ported. Wherever these fragments have rolled down to the waters’ 
edge or are so placed as to be inundated by the high tides, a very vig- 
orous growth of the green filamentous seaweed (Calothrix?) has 
appeared. I am not sure that it is more marked than the similar 
growth over the traps, sandstones and shales which were the previous 
occupants of the shores of the Island, and which have been somewhat 
displaced from their intimacy with the waves and currents of the Kill 
van Kull by these later arrivals, but it does seem to me as if it had 
developed with interesting rapidity. The schistose flaky character of 
many or most of these fragments may have conduced to facilitate this 
luxuriant development; and where, as in the case of granite veins, the 
feldspar is coarsely brecciated, the interlacing lines of angular defini- 
tion between the crystals offer a crevice for attachment. As a fact the a 
lamellar fragments are more quickly invaded. a 
Placing under a microscope flakes of mica, feldspar and quartz, we : 
can see the delicate filaments of the alga penetrating the films of the 
mica or occupying pits and irregular surfaces of the feldspar with dis- 
tributed spots of green granules. Sometimes lacunæ or minute cavi- 
ties, situated a little way within the edge of mica flakes, will be filled 
with the green spore-like groups. A few rude drawings show approx- 
imately some of the phases in this process of investment of the rock 
by the seaweed. say 
Cumulative effects have of late been much emphasized, and it is not cs 
unlikely that the alternating drying and swelling, from exposure to the — 
sun at low and submergence at high water, of this alga may sensibly 
determine the duration, as a mass, of the more schistose or friable 
rocks, when the tiny extensions of this subtle enemy have effected an 
entrance within their substance. : ge 
The American Psychological Association—Met at Phila- 
delphia, University of Pennsylvania, Tuesday and Wednesday, Dee. . 
27 and 28, 1892. On Tuesday, Dec. 27 there was a business meeting 
at which the nature of a permanent organization and other important - 
questions will be discussed. The following papers were read : : 
Errors of Observation in Physics and Psychology; Prof. J. McK. — 
Cattell, Columbia College; Experiments Upon Pain, Dr. Herbert — 
