350 ANNUAL OF SCIENTIFIC DISCOVERY. 



although there are evidences of the existence of a force requiring the same 

 conditions, viz. heat, moisture, oxygen, and a germ. In the lowest form of 

 animals the rudiments- of a nervous cell cannot be discovered; yet these 

 beings possess the attributes of vitality and even nervous force. These facts 

 point to the conclusion that nervous force is entirely distinct from the vital. 

 With reference to the circulation of the blood, Dr. Jones, after coming to the 

 conclusion that the heart is the smallest in fishes and the largest in birds, thus 

 illustrates the theoiy of the circulation : The number of beats of the pulse ir 

 a minute are in fishes generally from 20 to 24 ; in frogs, about 69 ; in birds, 

 from 100 to 200 ; the pigeon, common hen, and heron having respectively 

 130, 140, and 200. Taking animals in an ox the number is 38 ; a horse, 56 ; 

 a sheep, 75 ; an ape, 90; a dog, 90 to 95 ; a cat, 100 to 110 ; a hare, 120 ; 

 a guinea-pig, 140. In human beings, in the first year, the number is 115 to 

 130; second year, 100 to 115; third year, 90 to 100; about the seventh 

 year, 85 to 90 ; about the fourteenth year, 80 to 85 ; middle of life, 70 to 

 75 ; in old age, 50 to 65. Taking the mammalia generally, the range is 

 from 38 to 140. A close relation exists between the rapidity of the circu- 

 lation of the blood and the number of respirations in a minute. From this it 

 appears that cold-blooded animals are such, not from any peculiar chemical or 

 physical endowments of the organic or inorganic molecules of their bodies, but 

 from the peculiarity of structure of their circulatory and respiratory systems ; 

 and that the perfection of these two systems maybe taken as the index of the 

 rapidity of the physical and chemical changes of the molecules of their fluids 

 and solids, the intelligence and activity of the life-actions being proportional 

 generally to the rapidity and amount of the physical and chemical changes of 

 the organic and inorganic molecules. 



ON THE INFLUENCE OF LIGHT AND WATER ON THE GERMI- 

 NATION OF PLANTS. 



At the Albany meeting of the American Association, Mr. Jas. Dascomb 

 read a paper on the influence of light and water on the plumule and 

 radicle in the germination of plants. The theory heretofore held had been 

 that the plumule followed the light and the radicle avoided it. Shultz, of 

 Berlin, had made an experiment in which, by reflecting light upward from a 

 mirror to the mould containing the seed, the plumule grew down and the 

 radicle upward. Mr. Dascomb detailed several carefully conducted experi- 

 ments, the results of which did not tend to confirm the old theory. The 

 plumule invariably grew upward and the radicle grew downward rather than 

 upward. 



Prof. Agassiz said that for a number of years he had been making ana- 

 logous experiments. His were to ascertain whether the direction of the 

 plumule and radicle was not determined by something within the seed, in 

 order to obtain some analogy to the wings, arms, .and other extremities of the 

 body of animals. He sowed cresses in flower-pots, in different positions, and 

 the plumule always grew up while the radicle always grew down, into empty 

 space if there was nothing else there. 



