1892.] MICROSCOPICAL JOURNAL. 207 



By Mrs. William Streeter — Marine diatoms ; pollen on foot 

 of bee. 



By Dr. W. H. Seaman, Washington — Male and female firefly 

 and their luminous gland. 



By Miss Sarah F. Whiting, Wellsley, Mass. — Insect scales; 

 salt crystals. 



The exhibit lasted two hours, and the wonders of the micro- 

 scope seemed veritable miracles to some, who for the first time 

 peered through the tube. There were at least a hundred micro- 

 scopes, and every one of them was besieged by a line of eagerly 

 curious men and women. 



In one of the microscopes shown by Professor Griffith was a 

 bouquet of flowers. It was made of the scales of the butterfly 

 arranged with the most wonderful artistic skill in a space no 

 bigger than a pinhead. Another microscope revealed the Lord's 

 prayer through a pinhole. The exhibit which attracted the 

 largest share of attention and which, perhaps, was the most in- 

 structive w^as a series of nine microscopic objectives interspersed 

 with drawings showing the growth of the starfish at all stages. 

 This exhibit was prepared by Professor Charles Wright Dodge 

 and it was besieged all the evening by throngs of spectators. You 

 had to " get in line" and gradually work your way along. 



Another exhibition which attracted much attention was the cir- 

 culation of blood in the tail of a fish, shown by William Drescher. 

 This was accomplished in a most ingenious way. A living gold 

 fish was securely fastened in a small vessel containing just enough 

 water to keep it alive. Its tail was projected over the side of the 

 vessel, pressed between two small pieces of glass and firmly fixed 

 under the microscope. The power of the microscope was so high 

 that it resolved the blood, seen through the transparent covering 

 of the fish's tail, into countless little corpuscles, which gave it the 

 appearance of multitudinous grains of sand following each other 

 in and out and round about in endless procession up one aisle and 

 down another, constantly twisting and turning. An extra gold 

 fish lay in a pail of water by the side of the microscope so that the 

 fish on duty might be relieved should he give signs of foiling vital- 

 ity. Mr. Drescher stated that a fish would ordinarily accommo- 

 date the investigator in this way for an hour or an hour and half. 

 At the other end of the room was exhibited a frog's foot in similar 

 fashion. 



Professor Seaman, the secretary of the society, to whose energy 

 much of its vitality is due, exhibited a firefly under his lens. He 

 has made a special study of phosphorescent light in organisms 

 anrl says that the number of such insects is much larger than is 

 generally supposed and that the firefly is by no means alone in his 

 glory. 



Professor Rogers, the microscopic mathematician, exhibited 

 one twenty-fifth of an inch ruled off into loo equal parts — a sub- 

 division of the inch into 3,500 equal parts. Professor Rogers 



