37 6 
The Ohio Naturalist. 
[Vol. XV, No. 1, 
MEETING OF THE BIOLOGICAL CLUB. 
Orton Hall, March 2, 1914. 
The meeting was called to order at 7:30 by the President, 
Mr. Kostir; the minutes of the previous meeting were read and 
approved. 
C. J. Reed, R. R. Robinson and Percy Wiltberger were elected 
to membership. The First paper of the evening was by Prof. 
A. P. Weiss on “the Nature of Inhibition as a Nervous Function.” 
The paper considered a way in which the modification which 
occurs in all human instinctive reflexes as maturity is reached, 
could be explained by assuming that a nervous current may deflect 
a weaker one and thus bring about a combination of reflexes not 
present at birth, but which results in characteristically adult 
behavior. In this paper, inhibition (usually described as a check¬ 
ing or blocking mechanism) is considered as being a condition 
in which one nervous process deflects another and thus brings 
about a modification of the original response. 
The next part of the program was a symposium on “The 
Determination of Sex.” Prof. Sehaffner talked on sex determina¬ 
tion as demonstrated in plants. In some plants the sex can be 
changed; Equisetum for example, in which both gametophytes 
are produced from spores that look to be identical. In the higher 
plants the sex has been determined before reduction takes place. 
Miss Ickes explained the chromosome theory of sex determina¬ 
tion. According to this theory there is an accessory chromosome, 
the presence or absence of which determines the sex. Guyer 
found the accessory chromosome in guinea fowls, in chickens and 
in man. Nematodes and insects show the accessory chromosome. 
Prof. Barrows gave a short report of Dr. Riddle’s work with 
Dr. Whitman’s pigeons. If the eggs are taken away as soon as 
laid and a long series of eggs obtained, those at the beginning of 
the series will produce males while those toward the end of the 
series will produce females. In the middle of the series the 
individuals show graded psychological attributes. 
The meeting then adjourned. 
Blanche McAvoy, Secy. 
The twenty-fourth annual meeting of the Ohio Academy of 
Science will be held on November 26-28, at The Ohio State Uni¬ 
versity, Columbus. 
Date of Publication, November 5, 1914. 
