229 



which he had alive at his office, and that the Vorticolla after- 

 wards was propagated upon the skin of a Salamander, and upon 

 a piece of cork, kept in the same glass vessel with the worm. 

 The animalcule surmounts a flexible stem or pedicle, it is trans- 

 parent, and its mouth is surrounded by numerous cilia, which are 

 constantly in motion, and serve to keep the water in circulation 

 and to bring food near it. The Vorticellte, assuming a great 

 variety of elegant forms, with their pedicles at times partially 

 coiled in a spiral form, and at other times elongated, and with 

 the cilia in motion, producing a current carrying with it small 

 particles of water into the alimentary sack, were beautifully seen 

 upon the stand of the microscope. 



Dr. Bacon exhibited some very large and fine specimens of 

 Cystine, from the spontaneous deposit of the urinary excretion of 

 a person who has passed several Cystine Calculi within a few 

 months. This substance is of extremely rare occurrence here. 



Dr. Bacon also exhibited some Crystals of the Sulphate of 

 lodo-Quinine, a substance remarkable for its polarizing action, 

 and some Zeolitic Crystals of Carbonate of Lime, from the urine 

 of the horse. 



Dr. Durkee exhibited specimens of ValUsneria spiralis^ an 

 aquatic plant, growing in great abundance in Fresh Pond and 

 other waters. The circulatory fluid of the plant, running in 

 channels around the cells of which it is composed, was plainly 

 demonstrated by the microscope. 



Mr. Sprague exhibited specimens of an Alga which he found 

 in a sulphur spring near Portland, Me. It grew in abundance, 

 investing the neighboring grass, sticks, leaves, &c., with a soft 

 flaccid, snow-white fringe. It was found to consist, under the 

 microscope, of excessively slender, pellucid filaments, about a 

 line or more long, filled with minute granules, arranged in no 

 particular order. The filaments were simple, and attached firmly 

 to the object on which they grew. Mr. Sprague supposed that 

 it might be the Calothrix nwea, Ag. 



He also exhibited some of the minute fungi of the order Goni- 

 omycetes — Sporlde^miiim concinmtm and Sporidesmivm epiphyl- 

 lum. 



