Record. xxxiii 



sixty degrees in proportion to the increase of diameter of the base; and 

 it does not require a very great expanse of mouth area to give an angle 

 of ninety degrees, the one first assumed. 



This conclusion has a particular point of interest in the fact that it 

 indicates that the usual piezometer attachment to pipes for measuring 

 pressure heads is correct, their normal direction having no connection 

 with the sixty degree angle already discussed for the thin-edged pitot 

 tubes. 



Professor F. E. Nipher stated that he had obtained 

 results in recent experiments which seem to indicate 

 that the strength of a steel magnet depends upon its 

 electric potential. 



Mr. John E. Montague was elected to membership. 



Februaky 3, 1913. 



President Engler in the chair; attendance 15. 



The following donations to the Library were reported : 



J. J. Kessler A pamphlet on The Nitrile of Fumaric Acid. 



A. S. Langsdorf. .Two volumes of Science. 



Mr. Moses Craig read a paper on "Plant Improve- 

 ment by Selection." 



Mr. Craig briefly traced the history of plant breeding, outlining the 

 Darwinian and De Vriesian views of the origin of new forms, with 

 Mendel's law of character segregation. The importance of hybridiza- 

 tion in hastening variation was mentioned with methods of inbreeding 

 and methodical selection. He then gave many practical directions for 

 improving our pomaceous, cereal and vegetable crops. 



Dr. Chas. H. Turner read a paper on "An Apparent 

 Reversal of the Light Responses of the Common 

 Roach. ' ' 



The paper discussed a series of experiments conducted with the com- 

 mon roach (Periplaneta orientalis) for the purpose of seeing if the 

 negatively phototropic animal could be trained to refuse to enter a 

 specific dark place; and, if that proved possible, to experimentally 

 analyze the behavior. The electrical punishment method, devised by 

 Professor Yerkes, in his study of the dancing mouse, was used. 



According to the speaker this method has been used only once before 

 in the study of insect behavior; that was by Mr. Szymanski 6 in study- 

 ing the responses of several larval male cockroaches. A resume of 



6 Journal of Animal Behavior, 2:81-90. 1912. 



