I^g HODGE. [Vol. VII. 



that I would find little evidence of fatigue on such a day. On 

 second thought, however, I concluded to make a "rainy day" 

 experiment of it and see what might be the result. I little 

 expected the sharp and somewhat amusing result expressed in 

 the table. Not an observable sign of fatigue was to be seen 

 in the spinal ganglia ; while traces of fatigue were slight in the 

 cells of Purkinje. Perfectly clear, however, were the marks of 

 fatigue in the nuclei of the occipital cortex, as though, while 

 confined by the rain, the little birds had kept up a deal of think- 

 ing. The experiment is further complicated by the fact that 

 upon the night of February 14, in accordance with the time- 

 honored custom of St. Valentine's day, the boys had "shelled" 

 the windows of Worcester with peas. The subsequent thaw 

 had left them soft and swollen upon the surface of the snow ; 

 and as a result the crops and gizzards of the sparrows on Feb- 

 ruary 17 were filled with peas both morning and night. Indeed, 

 it would require but trifling effort on such a day of plenty for a 

 sparrow to lay in a supply of food sufficient for several stormy 

 days. 



In order to have represented in the plates as many experi- 

 ments upon as many of the different animals as possible. Figs. 

 8 and 9 were taken from the occipital cortex of Figs. 3 and 4. 

 These figures show fairly well the difference between the 

 morning and evening cells of the other birds. 



It will be specially noted (Figs. 8 and 9, and 12 and 13) that 

 whereas, in spinal ganglion cells with capsules, loss of sub- 

 stance in the protoplasm is shown by vacuolation with little 

 shrinkage of cell, in the cerebrum and cerebellum the cells 

 shrink bodily. This is expressed in part at least by enlarged 

 pericellular lymph spaces. 



Experiment IV was purposely made upon a warm, bright day, 

 April 22, when the sparrows were most busily at work nest- 

 building, with purpose also upon female sparrows. 



" Fur den Spatz ist das Plaisir, 

 Fiir die Spatzin sind die Pflichten ! " 



Effects of the day's work are seen from the table to be quite 

 evenly distributed over the parts of the nervous system exam- 

 ined. This is true for all cases except for No. Ill, the rainy 

 day experiment 



