JUNE 4, 1923 PROCEEDINGS: BIOLOGICAL SOCIETY 235 
the bug. If the parasite finds herself on the head of a male bug, she jumps 
to the female bug when the sexes couple. This interesting observation 
was recently made by an Entomologist in the Belgian Congo, Lieut. J. 
GHESQUIERE. 
Miss P. L. Boone directed attention to the early flowering of trailing 
arbutus, pansy violets, golden club, saxifrage, and skunk cabbage near Hyatts- 
ville, Md. 
Horace M. Awsricut, Superintendent, Yellowstone National Park: 
Protecting native wild life in Yellowstone National Park (illustrated by lantern 
slides and moving pictures). Park scenery and conditions and the larger 
animals were described and illustrated by still and moving pictures. The 
desirability of adding to Yellowstone National Park the region about the 
sources of the Yellowstone River and Teton Range was advocated. The 
larger game animals were said to be wintering in excellent condition. The 
number of buffaloes in the introduced herd was reported to be about 578, 
in the wild herd about 150. The antelope numbered about 350. Of several 
hundred mountain sheep occurring in the Park one hundred and forty-two 
had recently been seen. The sheep were reported to have entirely recovered 
from scab with which Park animals became infested a few years ago. 
Frank R. Liuuie, National Research Council: The problem of the sex 
hormones. The réle of the hormones in the differentiation of sex was dis- 
cussed. The precision with which hormones operate was stressed, sex being 
regarded as inherited like other characters, and the action of sex hormones 
regarded as intensifying the zygotic factors of the same sign and vice versa. 
Sex is determined at the time of fertilization in accordance with the chro- 
mosome complex, and not in accordance with environmental factors. Lip- 
schutz’s view that an embryo is essentially asexual until its sex is impressed 
upon it by hormones of the male or female type was shown to be untenable. 
The speaker also expressed the view that the effects of sex hormones are 
strictly limited in the case of the free-martin in cattle, though it is possible 
that they may vary in different species. The paper was discussed by A. 
A. Dootittie. The principal data are included in a paper to be published 
in the Biological Bulletin for February, 1923. 
E. A. GotpMan, Recording Secretary, protem. 
647TH MEETING 
The 647th meeting was held jointly with the Washington Academy of 
Sciences and affiliated societies in the auditorium of the National Museum 
February 3, 1923, in commemoration of the centenary of the birth of SPENCER 
F, Barrp. 
648TH MEETING 
The 648th regular meeting was held in the lecture room of the Cosmos 
Club, February 17, 1923, at 8.10 p.m., with President Hrrcucocx in the chair 
and 91 persons present. Mr. R. C. SHANNON was elected to membership. 
The President announced the appointment of E. A. Cuapin and H. C. 
OBERHOLSER as additional members of the Committee on Zoological Nomen- 
clature. 
Mr. M. B. Warre directed attention to an article in the Geographical 
Journal for January, 1923, describing an ascent of Mount Kilimanjaro. 
Interesting features were mentioned including the perfect volcanic cone with 
an ice cap inside of crater, and the distribution of plants in belts at different 
altitudes. 
