100 



The Ottawa Naturalist. 



[Sept. 



Precipitation and Amount of Nitrogen per Acre, Ottawa, 



1908-1911. 



Year ending 



February 29, 1908. 

 28,1909. 

 28,1910. 

 28,1911. 



Rain 



in 

 Inches 



Snow IpJSofta Pounds of 



in rrecipitd- Nitrogen 



tion in A s 



Inches per Acre 



Inches 



24.05 

 22.99 

 28.79 

 19.67 



133.0 

 96.25 

 80.75 

 73.00 



37.35 

 32.63 

 36.87 

 26.97 



4.322 

 8.364 

 6.869 

 5.271 



It will be observed that the present figure (5.271 lbs.) is 

 practically the mean of the amounts recorded for the two years 

 1908 and 1910. It probably represents therefore, approximately, 

 the amount of the nitrogen furnished per acre annually by the 

 rain and snow in the neighborhood of Ottawa. 



The analytical data show that of this amount, 4.424 lbs. 

 (approximately 84 per cent.), was contained in the rain, and 

 .847 lbs. in the snow. These proportions (though not the 

 amounts) are those of the previous year an interesting fact. 

 The data further indicate that of this total amount of nitrogen, 

 3.733 lbs. were present as ammonia compounds and 1.538 lbs. 

 as nitrates and nitrites, all of which from the agricultural point 

 of view may be considered of equal value, the ammonia com- 

 pounds readily undergoing conversion into nitrates (the form 

 in which plants absorb their nitrogen), in the soil. 



THE OCCURRENCE OF THE LARVA OF THE WAN- 

 DERER, FENISECA TARQUINIUS, IN NOVEMBER. 



By Albert F. Winn, Montreal. 



This butterfly, whose habits are wholly unlike those of any 

 other species in North America, has never been taken in any 

 numbers on the Island of Montreal, though it fairly abounds all 

 through the Laurentian hills within forty miles to our north, 

 wherever the alder and its clusters of woolly lice are found. 

 Students of insects are familiar with its curious life-history, and 

 extraordinary chrysalis, but the finding of the larvae feeding upon 

 the lice on the first of November, after we had had about two 

 nches of snow, was to me, at all events, rather unexpected and 



