204 [December, 



northern birds were very abundant. As yet, the bird alluded to has 

 not been ascertained to be accompanied by other species, but is more 

 abundant than during its visit in 1836-7. During an excursion in New 

 Jersey, a few miles from Philadelphia, Mr. C. stated that he saw not 

 only boys shooting crossbills in large numbers, but killing them with 

 stones, which their frequenting low pine trees, and their apparent entire 

 want of acquaintance with danger, rendered not difficult. They, in fact, 

 manifest the utmost simplicity of habits, showing even no signs of alarm 

 at the report of the gun, and continue quietly searching for food without 

 regarding the death of their companions. 



A collector of this city recently shot seventy-eight specimens in the 

 course of one morning, and Mr. Drexler, lately employed by the Academy 

 as taxidermist, shot twenty-seven specimens this day. It would appear 

 from the unsuspicious manners of these birds that they have migrated 

 from regions not settled by the white races of men, and their appearance 

 here in such large numbers may be considered as demonstrative that the 

 winter in the north either commenced unusually early, thus preventing 

 the maturity of the buds on which they subsist, or that it has been of 

 great severity. 



December 26t7i. 



Vice-President Bridges in the Chair. 



The Committees on papers by Mr. Joseph Jones, of Georgia, read 

 October 25th ; by Dr. Leidy, read Dec. 5th ; by Dr. Le Conte, read 

 Dec. 12th and 19th ; by Mr. Girard, read Dec. 12th ; by Mr. Cassin, 

 read Dec. 19th; by Dr. G-entb, read same date; by Dr. Wetherill, 

 read same date ; and by Mr. Isaac Lea, read Feb. 7th, 1854, severally 

 reported in favor of publication in the Proceedings. 



An Abstract of Experiments upon the Physical Influences exerted by hiving 

 Organic* and Inorganic , Membranes, upon Chemical Substances passing through 

 than by Endosmose. 



By Joseph Jones. 



The phenomenon of endosmose is coeval with that of life. All organized 

 beings spring from organic cells. Each cell is a chemical laboratory ; the mate- 

 rials for its nutrition, growth, and elaboration all pass through its walls by en- 

 dosmose. What is true of the organic cell, is also true of every living organ- 

 ism, however simple or complex, because all its acts of nutrition, secretion, and 

 growth, are carried on by organic cells. These facts show the important bear- 

 ing of endosmose upon physiology and pathology, and demonstrate the absolute 

 necessity of studying and understanding its phenomena, and developing, as far 

 as possible, all its physical laws. 



A true knowledge of these can only be gained by careful, laborious, and nu- 

 merous experiments. 



Experiments upon Living Animals, shoioing that their Membranes exert a 

 Physical Influence capable of changing the molecular arrangement of Chemi- 

 cal Substances in solution, passing through them by Endosmose. 

 Immersed the belly and lower extremities of a large spring-frog, in a strong 

 solution of the chloride of calcium, and allowed it to remain for an hour ; then 

 washing it carefully with water, immersed its lower extremities in a strong so- 

 lution of the oxalate of ammonia. It remained in this solution for one hour, 



