Journal of Applied Microscopy. "245 



and physical states, to know whether the chemical nature of the cells or the 

 form of their processes changes during activity or rest. 



The experiments were made to determine the condition of nerve cells in their 

 sleeping and waking states. Puppies were used, and it was hoped that by cutting 

 through the head quickly at one blow with a sharp, thin knife and allowing the 

 parts to fall into the fixing fluid, the cells would be hardened before their pro- 

 cesses could expand or contract in case any such change really did occur. 



To determine the condition of nerve cells during rest, a puppy after sleeping all 

 night was killed immediately upon waking, while for comparison its mate was left 

 playing all day until thoroughly tired and then killed after sleeping a few moments. 



The cells of the puppy that had slept all night showed the dendritic processes 

 well expanded, while the cell processes of the puppy that had played all day were 

 full of varicosities. This apparently contradicts the current theory that the cell 

 processes are in contact during activity and that the contacts are broken 

 during sleep, for the experiment shows that the varicose condition results from 

 exhaustion of the cell, and that the dendritic processes become expanded during 

 the resting condition. 



Prof. Conklin discussed " Protoplasmic Movements as a Factor of Differen- 

 tiation." He believes that the polarity of ova is not dependent upon gravity, 

 but is due to flowing movements of the protoplasm and that the position of the 

 centrosome and other organs of the cell is caused by these currents. He thinks 

 it is insufficient to say that changes in position of different organs of the cell are 

 brought about by chemotaxis, but these protoplasmic currents are the medium 

 through which chemotaxis acts. 



Prof. C. H. Eigenmann gave a paper entitled, " Further Observations on the 

 Eyesof the Blind Fishes." He is working on the Amblyopsidae, and told the society 

 that during the summer he had crawled through nine caves and secured eight 

 fishes of the type required. The forms in which the eye has not yet disappeared 

 are more favorable for study. The fishes of this family are all negatively helio- 

 tropic, and the eye is used only for the purpose of avoiding the light. In those 

 found outside of caves the retina is thin, while in inside forms it is thick, but in 

 both cases the eye is degenerating. 



The members of this family have a characteristic color pattern which extends 

 in lines along the upper, middle, and lateral portions of the body and is related 

 to the muscle bands. The pattern is always present, but with a varying degree 

 of color, and the amount of color present is not affected by the light. 



Mr. N. R. Harrington read a paper on the " Respiratory and Breathing 

 Habits of Polypterus." He does not accept the view that the Dipnoi may be 

 taken as ancestors of the air-breathing animals, because the special adaptations 

 they present are not for breathing air suspended in water, but for enduring long 

 periods of drouth by encasing themselves in mud. 



Attention was called to " A Specific Case of the Elimination of the Unfit " by 

 Dr. H. C. Bumpus. 



The unfit in this instance was the ubiquitous English sparrow, which had 

 been killed in large numbers during a severe ice storm. Measurements and 

 weights of the sparrows were taken, and the comparison of the results showed 



