356 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



the stalk at some distance from the leaf on the other, a cur- 

 rent is then indicated which is opposed to that in the leaf 

 current : this he calls the stalk current. After describing nu- 

 merous variations in this experiment, all tending to show that 

 feeble electric currents are passing through both leaf and 

 stalk, he states that, if the leaf is so placed on the electrodes 

 that a normal leaf current is indicated, and a fly be then al- 

 lowed to creep into the leaf, it is observed that the moment 

 the fly reaches the interior so as to touch the sensitive hairs 

 on the upper surface, the galvanometer needle springs to the 

 right if it had previously been deflected to the left, and the 

 leaf at the same moment closes on the fly. The fly, having 

 been caught, does not remain quiet ; and each time it moves 

 the needle again springs to the right. The same series of 

 phenomena present themselves if the leaf is touched with a 

 camel's-hair pencil. Proc. Roy. Soc, London, XXL, 495. 



SEA-WEEDS OF THE BAY OF FUNDY. 



Professor Eaton has published a list of the marine algae col- 

 lected near Eastport, Maine, in the summer of 1872, in con- 

 nection with the investigations of the United States Fish 

 Commission. The specimens w r ere gathered partly by him- 

 self, and partly by Messrs. Verrill, Prudden, Isham, and Pal- 

 mer. The list numbers fifty-six species, of which several are 

 recorded for the first time on the American coast. As the 

 collections were made only in the months of August and Sep- 

 tember, Professor Eaton thinks that many species yet remain 

 to reward the diligence of the gatherer. 



DIFFUSION OF POLLEN IN THE ATMOSPHERE. 



A very suggestive series of experiments has been made by 

 Mr. Blackly in connection with his researches upon the "hay 

 fever,'''' with a view to determine the extent to which pol- 

 len of various plants is diffused throughout the atmosphere. 

 His first series of inquiries was instituted in a meadow at 

 the average breathing level of four feet nine inches from the 

 ground, beginning in April and continuing until the end of 

 July. A slip of glass was exposed horizontally, coated with 

 a thin layer of non-drying liquid. The results were tabulated 

 daily; and the highest number of pollen grains obtained on 

 a square centimeter in 24 hours was 880, June 28th, Sudden 



