376 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. Schaffner talked on sex detemiina- 

 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 detennines 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. 



