Marcu 22, 1912] 
1911, while collecting material for an exhibition 
group of Petromyzen for the American Museum. 
The nests are depressions in the gravel of the 
river-bottom, two to three feet in diameter, and 
six inches deep at the center. The method of their 
construction and the general behavior of the speci- 
mens on the nest are very similar to those of the 
Brook Lamprey. But owing to the large size of 
this species all its movements can be minutely 
observed. 
To be published in full in The American Nat- 
uralist. 
On the Factors that Determine the Location of 
the Borings of the Yellow-bellied Sapsucker 
on the Paper Birch: MARGARET W. TAGGART, 
University of Illinois. (Introduced by Jacob 
Reighard.) 
The aim of the present study is to determine 
the details of the work of the yellow-bellied sap- 
sucker (Sphrapicus varius varius) upon the paper 
birch (Betula alba paprifera). The borings of 
the sapsucker on the birch are distributed in sey- 
eral separate areas on a single tree. These indi- 
vidual holes are arranged in definite rows: they 
are distinct, small, numerous and are rarely con- 
fluent. The birds as they excavate eat the 
sap and cambium of the tree and also the 
insects attracted by the liberated sap. The fac- 
tors involved in an explanation of the distri- 
bution of the groups of holes and in the shape 
and arrangement of the individual borings are 
two—the woodpecker instinct to bore holes and the 
mechanical conditions under which the bird works. 
The mechanical conditions resolve themselves into: 
(1) The perching of the bird. The sapsucker 
perches on knots and rough places on the bark, 
rather than on the smooth bark, and uses the 
excavations it has made in preference to the knots, 
because they afford a firmer foothold. (2) The 
structure of the bark. The shape of individual 
holes and the arrangement of series of holes in 
vertical colums is determined by the structure of 
the bark. (3) The use of the cambium as an 
article of diet. A flow of sap is released by the 
use of the cambium as an article of diet. The 
sap attracts insects as a purely incidental result 
of the bird’s work. (4) The cleaning up of all 
the cambium around the edges of the holes. The 
large denuded areas are formed as an accidental 
accompaniment to cleaning up all the cambium 
around the edges of the holes, and may or may not 
appear on a given tree. Any explanation, there- 
fore, which involves instinct or intelligence, more 
SCIENCE 
461 
than the general woodpecker instinct to make 
small holes, is unnecessary. The external factors 
are an adequate explanation of the facts in the 
ease. 
Provisional Tabulation of Some Brain Collections 
with Special Reference to their Usefulness for 
Taxonomic Purposes: Burt G. WILDER, Cornell 
University. 
The Brain of the New Goblin Shark: Wiuu1aM A. 
Locy, Northwestern University. 
Control by the Sympathetic Nervous System and 
its Morphological Basis: ALBERT KUNTZ, Uni- 
versity of Iowa. 
To be published in the Journal of Comparative 
Neurology. 
Nervous and Non-nervous Responses of Actinians: 
G. H. Parker, Harvard University. 
A few seconds after a mechanical or a chemical 
stimulus has been applied to the ectoderm of the 
lower part of the column of a sea-anemone (Me- 
tridium marginatum), the animal will respond by 
contracting the longitudinal entodermic muscles of 
the mesenteries, whereby the oral disk becomes 
retracted and ultimately covered by the action of 
the ring-muscle. The fibrillar layer in the base of 
the ectoderm and entoderm, believed by the Hert- 
wigs to be the nervous layer, does not offer an 
easy means of explaining this reaction, since it 
does not connect the ectoderm in any direct way 
with the longitudinal mesenteric muscles. Neither 
does this layer become stained or impregnated by 
any of the ordinary methods used for the demon- 
stration of nerve-cells or neurofibrils. By a modi- 
fied silver method devised by Dr. EH. G. Titus, a 
rich system of neurofibrils can be demonstrated in 
the supporting lamella of the column. These 
fibrils penetrate the ectoderm and reach through 
the supporting lamella of the mesenteries to the 
longitudinal mesenteric muscles. They are the es- 
sential nervous elements in the retraction reflex 
just mentioned. 
When a sea-anemone is cut nearly in two, 
nervous transmission from one piece to the other 
can be accomplished through almost any part of 
the body of the animal except the lips. Yet in the 
lips the so-called nervous layer of the Hertwigs is 
as well developed as in any other part of the body. 
This layer, therefore, probably is not the true 
nervous system; the true nervous system consists 
of the nervous elements imbedded in the support- 
ing lamella. The layer described by the Hertwigs 
as nervous is composed of the fine basal branches 
of the epithelial cells and may be a mechanism for 
