PEOFESSOR G. P. GIRDWOOD. 9 



develops from its original spore or seed to the fully developed individual, until fruetill- 

 cation occurs. From the spring to the autumn : In the daylight of spring there are present 

 more of the active rays — i. e., shorter and quicker vibrations — when life is most rapid, and 

 towards autumn the heat rays — longer and slower vibrations — predominate, when the seeds 

 are ripening ; so tliat these changes are brought about by the altered conditions surround- 

 ing the plant, and, of course, of its various cells, so that the cells themselves and their 

 functions are altered by the surroundings ; and this is further proved by the occasional 

 second growth of plants, or second crop, as it is sometimes called, brought about by the 

 atmospheric changes producing changes in the cells. ISTor is this all, for we can make new 

 individuals by the process of hybridizing ; that is, by selecting the pollen of one plant and 

 applying it to the stygma of another of its own kindred, within certain limits of con- 

 sanguinity ; in such cases by hybridizing, that is by introducing new molecular motions to 

 the primordial cell, it is possible not oidy to bring about permanent changes, but to predi- 

 cate what those changes will be, it may be to change the colour of the flower, increase the 

 size of the fruit, or add to it some new quality of taste or perfume. In animals also this can 

 be done, as is evidenced by breeding ; and in breeding the process is carried to the colour 

 of a feather. Again, a new molecular motion given to the embryo is found to permeate the 

 whole life of the individual and to produce the colour required. 



May it, then, be said that heredity is the impress of certain molecular vibrations, till 

 the}' become, as it were, ingrained in the cells of the individual. 



This seems to be the simple explanation of the facts noticed. In chemistry- these 

 phenomena are, perhaps, nioi-e clearly seen in the action of different crystals ami solutions, 

 of chemical substances in absorbing certain \'il)rati(ins of light, or of twisting them fruin 

 their course, tluis producing the beautiful phenomena of the spectroscope or polarized light, 

 thereby enabling chemists to estimate the quality as well as the quantity of the materials 

 by the effect produced. 



Among the latest new discoveries are the facts being worked out in regard to the sugars 

 and their artificial production, by Fisher, and the action of sugars and their solutions upon 

 polarized^liglit, and of the optically active varieties of tartaric and glyceric acids, and the 

 chemical constitution of these bodies, showing in the active bodies an asymmetrical carbon 

 atom and in the inactive a symmetrical one. 



Among the most remarkable facts noted is that by Frankland, that among the levo- 

 rotary sugars are those that are acted upon liy the micro-organisms producing fermentation, 

 whilst the dextro-rotary are not acted on ; thus : 



(CH, Oil) (CIL OH) 



-(C) (II) (Oil) -f (C) (II) (Oil) 



COOH (COOH) 



Dextro-rotary glyceric acid Levorotary acid destroyed 



not acted on. by bacillus. 



Perhaps the most remarkable and pregnant series of experiments of the past year were 

 those which led to the illustrations by Lord Kelvin and Mr. Dewar on liquid air, in which 

 Mr. Dewar had as much as tliree gallons of liquid air on the table, in sight of the audience, 

 not boiling, it being carefully insulated from surrounding bodies by a perfect vacuum, 

 through which radiant heat from surrounding bodies could not pass. These experiments. 



Sec. III., 1894. 2. 



