938 
prominent accessory. This means that the ac- 
cessory does not bear all the material which differ- 
entiates sex. It may further indicate that a second 
aecessory chromosome is in the process of for- 
mation. 
(2) The Puget Sound Marine Station was 
started as a seaside summer school of biology by 
the Washington State University. Later the other 
institutions of the state joined in the endeavor. 
In 1910 the educational institutions of other states 
were asked to cooperate in the work of the station. 
‘At present the following states have some of their 
institutions participating: Washington, Oregon, 
Idaho, Nebraska and Kansas. There is now pro- 
vided a good laboratory, furnished with running 
fresh and salt water and electric lights. A large 
dining hall and 50 walled tents provide the living 
quarters. A dredge boat and many small boats 
with nets give abundant means for visiting the 
various islands and collecting the desired material. 
The climate is dry, cool and pleasant for summer 
work. But the station’s greatest attraction is the 
almost inexhaustible supply of animal and plant 
life. The number and variety of species is un- 
usually great and the numbers of many species are 
countless. (One hundred and ten slides, made 
from photographs of the animals, were shown, 
giving a glimpse of the life of the islands of 
Puget Sound.) 
Observations on Protozoan Fauna of High Moun- 
tain Lakes of Colorado: C. H. EDMONDSON, 
Washburn College. 
During July and August, 1911, twenty-one lakes, 
situated along the Colorado divide in Boulder, 
Grand, Gilpin and Clear Creek counties were vis- 
ited and collections made from them with a view 
of studying the protozoan fauna of high altitudes. 
Of these twenty-one lakes, eighteen are 10,000 
feet or more in altitude, the highest being Summit 
Lake, 12,740 feet elevation. Collections were made 
on James Peak at 12,500 feet and on Mt. Evans 
at 13,000 feet. 
Silver Lake and Lake Eldora were sounded and 
dredged for bottom fauna. 
The lakes are shallow, Silver Lake, at its present 
height, is about fifty feet in depth; Lake Hldora 
about forty feet in depth. 
During the summer the temperature of these 
high lakes ranges from 40 degrees to 50 degrees F. 
Two species of Difflugia, found among others in 
the bottom of Lake Eldora, Difflugia lebes Penard 
and Difflugia curvicaulis Penard, are characteristic 
species of the deep lakes of Switzerland. Dr. 
SCIENCE 
[N.S. Vou. XXXV. No. 911 
Penard has suggested that species common to the 
deep Swiss lakes and high elevations where con- 
ditions resulting from glaciers exist may represent 
a remnant of a glacial protozoan fauna. 
Of the altitudinal range of the species observed 
the following is a summary: 
Ciliates—over 11,500 feet altitude .... 23 species. 
Ciliates—over 12,000 feet altitude .... 9 species. 
Flagellates—over 11,500 feet altitude . 13 species. 
Flagellates—over 12,000 feet altitude . 2 species. 
Sarcodina—over 11,500 feet altitude .. 54 species. 
Sarcodina—over 12,000 feet altitude .. 39 species. 
Sarcodina—at 13,000 feet altitude .... 2 species. 
The great altitudinal, as well as latitudinal 
Tange, of some of our common species of protozoa 
is shown by the fact that twenty-nine of the spe- 
cies found in the high lakes of Colorado have been 
reported from sea level in the oceanic island of 
Tahiti in the southern hemisphere. A classified 
list of protozoa of the lakes of Colorado will 
appear in the University of Colorado Studies. 
The Cerebrum of Necturus and the Problem of 
the Evolution of the Cortez: C. T. HERRICK, 
University of Chicago. 
The Asymmetrical Distribution of the Polian 
Vesicles and their Correlation with the Retractor 
Muscles of Thyone: J. W. Scott, Kansas State 
Agricultural College. 
As is well known, echinoderms have remarkable 
powers of regeneration. Under certain conditions 
Thyone eviscerates itself, throwing off the ten- 
tacles, esophagus, stomach, intestine, the calcareous 
ring, the ring canal with attached polian vesicles, 
the nerve ring, and the muscles which retract the 
esophageal ring. It was found that regeneration 
of all lost parts takes place after evisceration. 
However, to determine this fact it was necessary 
to study individual differences. For example, the 
number of polian vesicles varies from one to four, 
usually one, commonly two, occasionally three, 
rarely four. Both in size and number the polian 
vesicles show a strong tendency to occur on the 
left side. This asymmetrical distribution does not 
appear to have any present functional significance, 
and so must be referred to ancestral conditions. 
The additional fact was brought out that the num- 
ber of retractor muscles varies with the number 
of polian vesicles. The average number of re- 
tractor muscles per individual increases as the 
number of polian vesicles increases; this is true 
in particular for the left side. Even after regen- 
eration the same correlation holds true. The 
original asymmetry of each individual was re- 
